kawasin@google.com catan-team@chromium.org Records the result of AttemptFastKillForDiscard. Emitted immediately after the fast shutdown for the main frame renderer process attempt. vovoy@chromium.org fdoray@chromium.org The number of tabs discards since last emit. The emit interval is at least 24 hours, see metrics::DailyEvent for more details. The discards are requested {TabDiscardReason}. vovoy@chromium.org fdoray@chromium.org The number of tabs reloads since last emit. The emit interval is at least 24 hours, see metrics::DailyEvent for more details. The discards corresponding to the reloads are requested {TabDiscardReason}. fdoray@chromium.org catan-team@chromium.org The number of tabs discard candidates. This is recorded each time Chrome needs to urgently discard a tab. Warning this historgram was expired between 2024-04-28 and 2025-01-18. tluk@chromium.org catan-team@chromium.org Records whether the FrameTree discard operation succeeded. Emitted immediately after the FrameTree discard operation attempt. kalutes@chromium.org cros-core-systems-perf@google.com Logged after a tab is successfully discarded by PageDiscardingHelper::DiscardMultiplePages (includes urgent discards, but not discards by Performance Controls features such as Memory Saver or Performance Detection). Indicates whether the tab was focused at the time of discard. kalutes@chromium.org cros-core-systems-perf@google.com Logged after a tab is successfully discarded by PageDiscardingHelper::DiscardMultiplePages (includes urgent discards, but not discards by Performance Controls features such as Memory Saver or Performance Detection). Indicates whether the tab was protected at the time of discard. kalutes@chromium.org kawasin@chromium.org vovoy@chromium.org Reported for ChromeOS only. The latency since Chrome start handling a discard request and until the first tab discarding from the request completes. This is recorded when discarding tabs for the request completes in success. fdoray@chromium.org joenotcharles@google.com Reports the outcome of each discard tab attempt by the DiscardPagesOnUIThread function. Will be used to validate that the number of failures does not increase if DiscardAttemptMarker is retired (it was introduced to prevent repeated attempts to discard a non-discardable tab, but that shouldn't happen in practice). Use "Discarding.DiscardTabOutcome" to determine why there are samples in the "DiscardTabFailure" bucket. kalutes@chromium.org vovoy@chromium.org Reported for ChromeOS only. The count of tab discards that were unnecessary given the origin time of the memory pressure reclaim target. This is calculated and reported when Tab Manager or Page Discarder finish discarding tabs in response to a reclaim target. There can be a non-trival amount of time between when a memory pressure reclaim target is generated and when Chrome actually discards tabs in response to the reclaim target. If a reclaim target is generated before all tabs from the previous target have been discarded, then the same memory shortfall can be included in all of those signals' reclaim targets, resulting in Chrome discarding more tabs than is strictly necessary. fdoray@chromium.org joenotcharles@google.com Reports the outcome of each discard tab attempt by TabLifecycleUnit::Discard. Will be used to understand why we have samples in the "DiscardTabFailure" bucket of "Discarding.DiscardPageOnUIThreadOutcome". kalutes@chromium.org kawasin@chromium.org vovoy@chromium.org Reported for ChromeOS only. The latency since a critical memory pressure signal is sent from resourced and until Chrome start handling the discard request. This is recorded when discarding tabs for the request completes in success. kalutes@chromium.org vovoy@chromium.org Reported for ChromeOS only. The age of the memory pressure signal when it is processed by the tab/page discarder. This is recorded when Tab Manager or Page Discarder reads the signal, but before any tabs are discarded as a result of the signal. tluk@chromium.org catan-team@chromium.org Records discard latency for the TabLifecycleUnit::Discard() operation. For the discard implementation that replaces the discarded tab's WebContents this is measured as the time from when a TabLifecycleUnit::Discard() is called for a tab, to when the Tab's WebContents is replaced. This is emitted immediately after the Tab's WebContents is replaced. For the discard implementation that retains the discarded tab's WebContents this is measured as the time from when a TabLifecycleUnit::Discard() is called for a tab, to when the Discard() operation was completed in the renderer and completion was acknowledged by the Browser or when the frame's renderer is terminated. This is emitted immediately after the acknowledgement of the Discard operation by the RenderFrameHost in the Browser or once the frame is notified its renderer has terminated. The retained discard implementation is behind the WebContentsDiscard flag and eventually the old implementation that replaces the WebContents will be removed. ewannpv@chromium.org gambard@chromium.org bling-team@google.com The age of a Tab when closed (Time between creation time on the current device and closure time). ckitagawa@chromium.org clank-tab-dev@chromium.org [Android] Records the latency for a tab discarded for {DiscardReason}. Emitted after the tab discard callback is run. Note that discard might not run the callback or might not have happened in the event the tab is not discardable. ckitagawa@chromium.org clank-tab-dev@chromium.org [Android] Records the reason for starting a tab discard. Emitted when a Tab discard is started. ckitagawa@chromium.org clank-tab-dev@chromium.org [Android] Records lifecycle milestones and failure states of the GracefulShutdownService during window closure. polardz@google.com clank-tab-dev@google.com [Android] Records the media state of the tab when it changes. If multiple states apply, the priority is Sharing > Recording > Audible/Muted > None. wnwen@chromium.org [Android] Count of upload success/failures by crash type. {AndroidCrashUploadTypes} ckitagawa@chromium.org fredmello@chromium.org Records whether the "Close all tabs" action was taken when the close all tabs confirmation dialog was shown through App Menu > Close all tabs. This is only recorded for Android for {CloseType} close all tabs menu actions. hitarthkothari@google.com ckitagawa@chromium.org clank-tab-dev@chromium.org Records the SnackbarIdentifier of a tab-closure-related undo snackbar when it is dismissed without the user performing the Undo action (e.g. timeout, swipe, dismissed by caller, etc.). hitarthkothari@google.com ckitagawa@chromium.org clank-tab-dev@chromium.org Records the SnackbarIdentifier of a tab-closure-related undo snackbar when the user actively clicks the Undo action. dpenning@chromium.org top-chrome-desktop-ui@google.com The number of selected tabs when the user selects {TabContextMenuCommand} from the tab context menu. rhalavati@chromium.org chrome-incognito@google.com Number of open tabs in each guest window. Recorded once a new tab in a guest window is opened and adds one to the bucket of number of tabs in that particular window (it does not count the total number of tabs in all open guest windows). Please note that this metric double counts the lower numbers, meaning that if user opens three tabs (without closing any in between), then buckets 1, 2, and 3 will all be incremented in turn. The metric also overcounts the tabs that are moved from one window to another as they are recorded both when they are created in the first window and when they are added to the second window. rhalavati@chromium.org chrome-incognito@google.com Number of open incognito tabs in each window. Recorded once a new incognito tab is opened in a window and adds one to the bucket of number of incognito tabs in that particular window (it does not count the total number of incognito tabs in all open windows). Please note that this metric double counts the lower numbers, meaning that if user opens three tabs (without closing any in between), then buckets 1, 2, and 3 will all be incremented in turn. The metric also overcounts the tabs that are moved from one window to another as they are recorded both when they are created in the first window and when they are added to the second window. aattar@google.com catan-team@chromium.org Recorded when a discarded tab begins to reload. Returns true if the tab was focused at the moment the reload started (indicating an explicit user switch), and false if it was a background reload. aattar@google.com catan-team@chromium.org Recorded when a discarded tab finishes reloading. Tracks the estimated memory (in MB) that was originally freed when this tab was discarded. Correlate with Reload.LoadTime to determine efficiency. aattar@google.com catan-team@chromium.org Recorded when a discarded tab finishes reloading. Measures the duration from DidStartLoading to DidStopLoading. aattar@google.com catan-team@chromium.org Recorded when a discarded tab begins to reload. Measures the time elapsed since the tab was originally discarded. Short times indicate high "user regret." olivierrobin@chromium.org bling-team@google.com [iOS] Used on External App launcher Prompt to determine how the user interacted with the prompt. dpenning@chromium.org top-chrome-desktop-ui@google.com [Desktop] Records different types of tab grouping transition states 10 seconds after a tab is created. Replaces Tab.GroupingTransition. gambard@chromium.org bling-team@google.com [iOS] Whether a page has a custom under page background color, recorded when the page is fully loaded. The default value of this color is from the background colors of the "html" and "body" elements and the background color of the web view. By default it is white, so this histogram only records it as custom if it is not white with no alpha. gambard@chromium.org bling-team@google.com [iOS] Whether a page has a theme-color html tag set, recorded when the page is fully loaded. gjc@google.com chrome-loading@google.com Records the duration of TabIcon::UpdateThrobber calls. Recorded when the tab's throbber is updated. This captures fast cached cases as well as slow layer creation/destruction cases. This metric is only reported for clients with high-resolution clocks. gjc@google.com chrome-loading@google.com Records the duration of TabIcon::UpdateThrobber calls that result in actual layer creation or destruction. Recorded when the tab's throbber is updated and results in actual layer creation or destruction. This metric is only reported for clients with high-resolution clocks. bsep@chromium.org Recorded when a new tab is opened. Tracks the method in which the tab was opened. Does not apply to opening existing links or searches in a new tab, only to brand new empty tabs. Note: Currently the "Regular menu option" includes some programmatic actions in addition to user actions. dtrainor@chromium.org ckitagawa@chroimum.org [Android] The number of page loads since the last switch to an evicted tab on Android. This was sampled each time an evicted tab was reloaded. Note that this data is invalid from M77 until 2023-11-22 because this histogram was expired. As of right now, this histogram is only emitted in iOS. ckitagawa@chromium.org dtrainor@chromium.org yfriedman@chromium.org [Android] User-perceived load time for a successful tab restore, measured from the first time the user sees the tab being restored until the load completes. Warning this historgram was expired between M89 and 2022-08-24. madhavpruthi@google.com ckitagawa@chromium.org clank-tab-dev@google.com [Android only] Records the total time for which a tab was pinned within a single session. The value is the duration between the tab being pinned and when it was unpinned. dominicaustria@google.com dfried@chromium.org collinbaker@chromium.org On tab switch, the visible content area is captured and stored as a thumbnail. This measures the time between requesting the capture and storing it as the current thumbnail. chazzy@chromium.org dfried@chromium.org When generating a preview for a background tab, this measures the time between starting a video capture and storing the first usable frame as the current thumbnail. huitingyu@google.com bling-pandamonium@google.com Record the action executed when the user performs a pull down gesture. This feature is currently iOS only. A pull down gesture is an action completed when the user scrolls past the edge of the web page and continues scrolling in the same direction revealing a specific UI on the header with multiple actions icons. The user can then choose an action by scrolling left or right and lift the finger or cancel by scrolling back up. This is currently an iOS specific feature. Expired 2025-05. Revived July 2025. justincohen@chromium.org bling-fundamentals@google.com [iOS] A count of the number of alive renderers in the current window when a renderer termination occurs. Expired for M78-94. pkl@chromium.org [iOS] The number of renderers which are either currently alive or recently terminated in the current window at the time of a renderer termination. justincohen@chromium.org thegreenfrog@chromium.org [iOS] The number of tabs of the current window at the time of a renderer termination. gambard@chromium.org olivierrobin@chromium.org The state (foreground/background) of a tab when its renderer is terminated. ckitagawa@chromium.org marq@chromium.org [Android and iOS] The status of a tab collected each time the user switches to it on mobile. That does not include tabs being created at the time the user switches to them, such as NTP or tabs opened to handle intents. However, it does include the Tab opened/restored when launching an Activity (on Android). Warning this histogram was expired between M86 and 2022-08-24. In M130, this metric was updated to include Custom Tabs on Android, which were probably unintentionally excluded. dtrainor@chromium.org ckitagawa@chroimum.org [Android] Age (in ms) when the tab was switched to foreground. Note that this data is invalid from M85 until 2023-11-22 because this histogram was expired. In M130, this metric was updated to include Custom Tabs on Android, which were probably unintentionally excluded. ckitagawa@chromium.org polardz@google.com Records the progress of new tab animations on Android to detect freezes. The animation is split into multiple parts, each with its own histogram. {AnimationType} wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records number of tabs within an archived tab group closed by pressing the X button on the tab group in the inactive surface. bjfong@google.com wylieb@google.com evanluo@google.com clank-tab-dev@google.com (Android only) Records the duration of an auto-delete pass for tab groups. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records when archived tab groups are closed through the "Close all inactive tabs" button in inactive pane. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records number of tabs within archived tab groups closed through the "Close all inactive tabs" button in inactive pane. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records when archived tab groups are closed through the "Close tab" menu item after user selects which tab groups to be closed. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records number of tabs within archived tab groups closed through the "Close tab" menu item after user selects which tab groups to be closed. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records when tab groups are closed locally due to the synced tab group being deleted elsewhere (e.g. another device logged into same account). dpenning@chromium.org top-chrome-desktop-ui@google.com The number of tabs groups that are collapsed in all browsers (counting app-mode windows) when a load completes. Prior to M-121, this was also recorded when a navigation in a non-tab WebContents (e.g. DevTools, extension popups) happens. Such a navigation would not have affected the recorded value. It would only duplicate a previous recording. huitingyu@google.com bling-pandamonium@google.com [iOS] The number of tab groups opened at cold launch. kunaldaftari@google.com top-chrome-desktop-ui@google.com Recorded when the user enters Tab Groups Focus Mode, categorizing the entrypoint used. kunaldaftari@google.com top-chrome-desktop-ui@google.com Recorded when the user or browser exits Tab Groups Focus Mode, categorizing the exit reason. kunaldaftari@google.com top-chrome-desktop-ui@google.com Recorded when the user exits Tab Groups Focus Mode. Records true if a pinned tab was activated at least once during the focus mode session, and false otherwise. kunaldaftari@google.com top-chrome-desktop-ui@google.com Recorded when the user exits Tab Groups Focus Mode. Records the number of times a pinned tab was activated during the focus mode session. kunaldaftari@google.com top-chrome-desktop-ui@google.com Recorded when the user exits Tab Groups Focus Mode. Records true if at least one pinned tab existed in the tab strip at any point during the focus mode session, and false otherwise. kunaldaftari@google.com top-chrome-desktop-ui@google.com Recorded when the user exits Tab Groups Focus Mode (or closes the window while in focus mode). Measures the duration the user spent in focus mode. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the percentage of stored entries in the saved tab group DataTypeStore that failed to parse as a SavedTabGroupData in the final stage of startup. Recorded during SavedTabGroupSyncBridge initialization after sucessfully passing through the migration stages. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records when archived tab groups are restored through the "Restore all" option menu item. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records number of tabs within archived tab groups restored by the "Restore all" option menu item. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records when archived tab groups are restored through the "Restore tab" menu option after user selects which tab groups to restore. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records number of tabs within archived tab groups restored by user selecting tab groups and using the "Restore tab" menu option. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records number of tabs within an archived tab group restored by user opening the synced tab group from the tab group pane. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records number of tabs within archived tab groups restored by user manually clicking into the tab group in the inactive surface. dljames@chromium.org top-chrome-desktop-ui@google.com Records per hour once the TabGroupSyncService is instantiated upon profile open. Tracks the total number of active groups (groups that have been modified within the last 30 days) saved in the profile. Nothing is recorded for sessions shorter than one hour. dljames@chromium.org top-chrome-desktop-ui@google.com Records once per group per hour once the TabGroupSyncService is instantiated upon profile open. Tracks the age of a SavedTabGroup (since creation). Nothing is recorded for sessions shorter than one hour. dljames@chromium.org top-chrome-desktop-ui@google.com Records per hour once the TabGroupSyncService is instantiated upon profile open. Tracks the total number of groups saved in the profile. Nothing is recorded for sessions shorter than one hour. dljames@chromium.org top-chrome-desktop-ui@google.com Records when a SavedTabGroup is deleted. Tracks the total age / lifespan of a SavedTabGroup (since creation) once deleted. Nothing is recorded for sessions shorter than one hour. dpenning@chromium.org top-chrome-desktop-ui@google.com Records per hour once the TabGroupSyncService is instantiated upon profile open. Tracks the total number of open groups (groups that are in the platforms "tabstrip") saved in the profile. Nothing is recorded for sessions shorter than one hour. dominicaustria@google.com yuhengh@chromium.org top-chrome-desktop-ui@google.com Tracks the type of tab group submenu that a user used to open a saved tab group. dljames@chromium.org top-chrome-desktop-ui@google.com Records per hour once the TabGroupSyncService is instantiated upon profile open. Tracks the total number of pinned groups saved in the profile. Nothing is recorded for sessions shorter than one hour. shaktisahu@chromium.org top-chrome-desktop-ui@google.com Records the difference in the number of tabs between local tab group and its synced counterpart when the synced version has more tabs compared to the local version. Recorded on connect which happens on startup and also when sync is turned on from an off state. shaktisahu@chromium.org top-chrome-desktop-ui@google.com Records the difference in the number of tabs between local tab group and its synced counterpart when the local version has more tabs compared to the synced version. Recorded on connect which happens on startup and also when sync is turned on from an off state. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Histogram for recording various steps of the SavedTabGroupSyncBridge initialization, such as the migration steps and their results. Care has been taken to ensure that a certain step isn't recorded more than once during a chrome session. Recorded on startup. dljames@chromium.org top-chrome-desktop-ui@google.com Records once per group per hour once the TabGroupSyncService is instantiated. Tracks the number of tabs in a SavedTabGroup. Nothing is recorded for sessions shorter than one hour. dljames@chromium.org top-chrome-desktop-ui@google.com Records once per saved tab per saved group per hour once the TabGroupSyncService is instantiated upon profile open. Tracks the duration since a saved tab's last modification. Nothing is recorded for sessions shorter than one hour. dljames@chromium.org top-chrome-desktop-ui@google.com Records once per group per hour once the TabGroupSyncService is instantiated upon profile open. Tracks the duration since a saved group's last modification. Nothing is recorded for sessions shorter than one hour. dljames@chromium.org top-chrome-desktop-ui@google.com Records per hour once the TabGroupSyncService is instantiated upon profile open. Tracks the total number of unpinned groups saved in the profile. Nothing is recorded for sessions shorter than one hour. ckitagawa@chromium.org clank-tab-dev@google.com Recorded on Android when a user switches tabs. Records whether the tab that was selected was in a tab group. dljames@chromium.org top-chrome-desktop-ui@google.com [ All platforms ] Tracks the number of times a shared tab group was deleted. Recorded when a shared tab group is deleted. dljames@chromium.org top-chrome-desktop-ui@google.com [ All platforms ] Tracks the number of times the last tab was closed in a shared tab group. Recorded when the last tab is closed in a shared tab group. Replaces TabGroups.Shared.LastTabClosed. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the result of loading a SharedTabGroupData entry from disk. Recorded on browser startup or profile open for each entry in the store. dljames@chromium.org top-chrome-desktop-ui@google.com [ Desktop ] Tracks the type of manage action a user explicitly performs on a shared tab group such as clicking the share / manage group button, or deleting a shared group. Recorded when a user triggers a manage action. dljames@chromium.org top-chrome-desktop-ui@google.com [ Desktop ] Tracks the type of recall action a user explicitly performs on a shared tab group such as closing a group but not deleting it, or opening a group from the bookmarks bar. Recorded when a user triggers a recall action. dljames@chromium.org top-chrome-desktop-ui@google.com [ All platforms ] Tracks the age of a SavedTabGroup (since creation). Only records if the data sharing feature is enabled. Recorded once per group on startup 10 seconds after TabGroupSyncService initialization. Replaces TabGroups.Shared.TabGroupAge. dljames@chromium.org top-chrome-desktop-ui@google.com [ All platforms ] Tracks the number of total shared tab groups on startup which includes both open and closed tab groups. Only records if the data sharing feature is enabled. Recorded on startup 10 seconds after TabGroupSyncService initialization. Replaces TabGroups.Shared.TotalTabGroupCount. dljames@chromium.org top-chrome-desktop-ui@google.com [ All platforms ] Tracks the number of tabs in a shared tab group. Only records if the data sharing feature is enabled. Recorded once per group on startup 10 seconds after TabGroupSyncService initialization. Replaces TabGroups.Shared.TotalTabGroupTabCount. qinmin@google.com chrome-multiplayer-eng@google.com Records whether a tab in a shared tab group uses page URL as its title, if the page is http(s) and optimization guide is enabled to retrieve the alternative title. Recorded when a tab is added to a shared tab group, or when a tab in a shared tab group finishes a navigation, or after the tabgroup owning the tab was converted to a shared group. No metrics are recorded for tabs in non-shared tab groups. This is recorded on all platforms. dljames@chromium.org top-chrome-desktop-ui@google.com [Desktop] Records when a keyboard shortcut for a tab group action is triggered. Tracks the number of times each tab group shortcut is used. Ex: - Creating a new tab group - Closing a tab group - Focusing the next / previous tab group - Adding the new tab to a tab group shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the percentage of stored entries in the saved tab group DataTypeStore that failed to parse as a SavedTabGroupSpecfics during migration to SavedTabGroupData. Recorded during the one-time migration. If the data is already migrated, this histogram is not recorded. shaktisahu@chromium.org clank-tab-dev@google.com Tracks the number of active tab groups on startup. A group is active iff there was explicit user interaction with the group in last {NumberOfDays} days. An explicit user interaction is currently defined as a tab addition, tab removal or a tab navigation inside the group. Recorded on startup 10 seconds after TabGroupSyncService initialization. Android and iOS only. dpenning@chromium.org top-chrome-desktop-ui@google.com Records whether a newly saved tab group was empty or not. Recorded on all platforms (Android, iOS, Desktop) whenever a tab group is added to the SavedTabGroupModel by syncing it from another device. Note that since messages are not received/processed in any particular order, it should not be surprising if this is a large value; however, each empty group should be filled, so the counts should be similar to TabAddedToEmptyGroupFromSync. dpenning@chromium.org top-chrome-desktop-ui@google.com Records whether a newly saved tab group was empty or not. Recorded on all platforms (Android, iOS, Desktop) whenever a tab group is added to the SavedTabGroupModel by the local device. shaktisahu@chromium.org clank-tab-dev@google.com Tracks the number of closed tab groups on startup. Recorded on startup 10 seconds after TabGroupSyncService initialization. Android and iOS only. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records whether a tab group that was closed by user has non-empty title. Recorded when the group is closed due to the user action which could be a deletion, ungroup or close action via UI. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records whether a tab group that was opened by user has non-empty title. Recorded when the group is opened from revisit surface. shaktisahu@chromium.org clank-tab-dev@google.com Tracks the number of tab groups that are deleted on startup due to a forced cleanup. This is only enabled for a certain finch group of users who have network layer disabled. Recorded on startup after TabGroupSyncService initialization after notifying the observers. Android only. shaktisahu@chromium.org clank-tab-dev@google.com Tracks the number of open tab groups on startup. Recorded on startup 10 seconds after TabGroupSyncService initialization. Android and iOS only. shaktisahu@chromium.org clank-tab-dev@google.com Tracks the number of active tab groups on startup that were remotely created. A group is active iff there was explicit user interaction with the group in last {NumberOfDays} days. An explicit user interaction is currently defined as a tab addition, tab removal or a tab navigation inside the group. Recorded on startup 10 seconds after TabGroupSyncService initialization. Android and iOS only. shaktisahu@chromium.org clank-tab-dev@google.com Tracks the number of active tab groups on startup that were remotely created. Recorded on startup 10 seconds after TabGroupSyncService initialization. Android and iOS only. shaktisahu@chromium.org clank-tab-dev@google.com Tracks the age of a SavedTabGroup (since creation). Recorded once per group on startup 10 seconds after TabGroupSyncService initialization. Android and iOS only. shaktisahu@chromium.org clank-tab-dev@google.com Tracks the number of tabs in a SavedTabGroup. Recorded once per group on startup 10 seconds after TabGroupSyncService initialization. Android and iOS only. shaktisahu@chromium.org clank-tab-dev@google.com Tracks the duration since a saved tab's last modification. Recorded once per tab on startup 10 seconds after TabGroupSyncService initialization. Android and iOS only. dpenning@chromium.org top-chrome-desktop-ui@google.com Records whether a tab added to a saved group was the first tab or not. Recorded on all platforms (Android, iOS, Desktop) whenever a tab is added to a tab group by syncing it from another device. dpenning@chromium.org top-chrome-desktop-ui@google.com Records whether a tab added to a saved group was the first tab or not. Recorded on all platforms (Android, iOS, Desktop) whenever a tab is added to a tab group by the local device. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab group was created. Recorded when the group is closed. This includes all types of group closures initiated by the user such as close, ungroup or delete event on the group. shaktisahu@chromium.org clank-tab-dev@google.com Records the source from which a tab group was closed. Recorded whenever a group is being closed in the UI which could be due to various trigger sources such as manually closed by user or deletion from sync. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab group was created. Recorded when the group is created. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab group was created. Recorded when the group is opened due to user action such as opening the group from revisit surface. shaktisahu@chromium.org clank-tab-dev@google.com Records the source from which a tab group was opened. Recorded whenever a group is being opened in the UI which could be due to various trigger sources such as manually opened by user or auto-opened from sync. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab group was created. Recorded when the group is removed. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab group was created. Recorded when a tab was added to the tab group. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab group was created. Recorded when a tab was navigated in the tab group. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab group was created. Recorded when a tab was was removed from the tab group. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab group was created. Recorded when the a tab is selected by user action. Note that this can happen multiple times during a user session. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab was created. Recorded when the a tab is selected by user action. Note that this can happen multiple times during a user session. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab group was created. Recorded when the tabs are reordered inside the group. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab group was created. Recorded when the group is interacted with by user. Tab addition, removal and selection are considered as user interaction shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records whether a tab group that was interacted by user has non-empty title. Tab addition, removal and selection are considered as user interaction. Note that this can happen multiple times during a user session. shaktisahu@chromium.org chrome-multiplayer-eng@google.com Records the DeviceType of the device in which a tab group was created. Recorded when the group visuals (title or color) is changed. dpenning@chromium.org top-chrome-desktop-ui@google.com Records whether a tab group loaded from disk was empty, not empty, or if it became empty after removing tabs already in a shared group. Recorded on all platforms (Android, iOS, Desktop) on browser startup or profile open for each saved or shared tab group loaded. shaktisahu@chromium.org clank-tab-dev@google.com Records the number of characters in the tab group title. Recorded when TabGroupSyncService::UpdateVisualData is invoked which is typically invoked whenever there is any change to title, color, or even when tab group dialog is closed. dpenning@chromium.org top-chrome-desktop-ui@google.com Records whether a tab removed from a saved group was the last tab or not. Recorded on all platforms (Android, iOS, Desktop) whenever a tab is removed from a tab group. shaktisahu@chromium.org clank-tab-dev@google.com Tracks the duration since a saved group's last user interaction which is typically defined as tab addition, tab removal or tab navigation. Recorded once per group on startup 10 seconds after TabGroupSyncService initialization. Android and iOS only. shaktisahu@chromium.org clank-tab-dev@google.com [ All platforms ] Tracks the number of total tab groups on startup which includes both open and closed tab groups. Recorded on startup 10 seconds after TabGroupSyncService initialization. bjfong@google.com wylieb@google.com evanluo@google.com clank-tab-dev@google.com (Android only) Records the number of tabs within a tab group that is autodeleted. bjfong@google.com wylieb@google.com evanluo@google.com clank-tab-dev@google.com (Android only) Records how old, in days, a tab group is when it's checked for auto-deletion eligibility. Recorded at startup when the archived tab model is loaded and at regular intervals after that (same cadence as tabs). Only recorded if tab group declutter is enabled. sophiechang@chromium.org top-chrome-desktop-ui@google.com Records the number of tabs in a group whenever a tab group editor bubble closes. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records number of tab groups that are archived due to tab group declutter. wylieb@google.com evanluo@google.com clank-tab-dev@google.com Records number of tabs within each archived tab group that are archived when the tab group is archived. huitingyu@google.com bling-pandamonium@google.com [iOS] The number of tabs per group at cold launch. dljames@chromium.org top-chrome-desktop-ui@google.com Records once an hour once the TabGroupSyncService is instantiated upon profile open. Tracks the number of unsaved TabGroups. Nothing is recorded for sessions shorter than one hour. dljames@chromium.org top-chrome-desktop-ui@google.com Records once per group per hour once the TabGroupSyncService is instantiated. Tracks the number of tabs in an unsaved TabGroup. Nothing is recorded for sessions shorter than one hour. dpenning@chromium.org top-chrome-desktop-ui@google.com The number of tabs groups with a user-set name or color open in all browsers (counting app-mode windows) when a load completes. Prior to M-121, this was also recorded when a navigation in a non-tab WebContents (e.g. DevTools, extension popups) happens. Such a navigation would not have affected the recorded value. It would only duplicate a previous recording. ckitagawa@chromium.org meiliang@chromium.org This histogram records the number of tab groups whenever Chrome comes to the foreground. dpenning@chromium.org top-chrome-desktop-ui@google.com The number of tabs groups open in all browsers (counting app-mode windows) when a load completes. Prior to M-121, this was also recorded when a navigation in a non-tab WebContents (e.g. DevTools, extension popups) happens. Such a navigation would not have affected the recorded value. It would only duplicate a previous recording. dpenning@chromium.org top-chrome-desktop-ui@google.com The number of pinned tabs in the tabstrip in all browser windows, when a page load completes. Prior to M-121, this was also recorded when a navigation in a non-tab WebContents (e.g. DevTools, extension popups) happens. Such a navigation would not have affected the recorded value. It would only duplicate a previous recording. treib@chromium.org shaktisahu@chromium.org clank-tab-dev@google.com Records the number of {GroupsOrTabs}, at the moment when the user is {ConsentLevel} Chrome. Android and iOS only. fdoray@chromium.org catan-team@chromium.org Cumulative number of tabs discarded due to low memory conditions, recorded once per tab discard event. For example, a user who had 3 tabs discarded records a count in the 1 bin, 2 bin and 3 bin. Thus each bin N is the number of sessions where users experienced N or more tab discard events. fdoray@chromium.org catan-team@chromium.org Elapsed time between a tab getting discarded to eventually being reloaded by the user. fdoray@chromium.org catan-team@chromium.org Elapsed time between the time a tab switched from being active to inactive (that eventually gets discarded) until it gets reloaded. fdoray@chromium.org catan-team@chromium.org Cumulative number of discarded tabs that have been reloaded by the user, recorded once per tab discard event. For example, a user who had 3 tabs reloaded records a count in the 1 bin, 2 bin and 3 bin. Thus each bin N is the number of sessions where users experienced N or more tab reload events. fdoray@chromium.org catan-team@chromium.org Elapsed time between the last time a discarded tab was reloaded and the time it gets closed. sreejakshetty@chromium.org chrome-brapp-loading@google.com Recorded when the user restores a {RestoreType}. The value is the time duration between the previous closing of the {RestoreType} and the {RestoreType} being restored. emshack@chromium.org top-chrome-desktop-ui@google.com When a tab is activated, records the index of that tab in the tab strip, starting at 1 (1-indexed). emshack@chromium.org top-chrome-desktop-ui@google.com When a tab is activated, records the index of that tab in the tab strip as a percentage of the total number of tabs. huitingyu@google.com bling-pandamonium@google.com [iOS] Records the number of tabs that are considered active as per the current tab inactivity threshold. This is recorded at cold launch. wylieb@google.com clank-tab-dev@google.com (Android only) Records how many tabs were restored. Recorded when a user restores tabs from the archived tabs dialog, selects the "close all tabs" button, or opens an archived tab. wylieb@google.com clank-tab-dev@google.com (Android only) Records how many tabs were archived prior to hitting the maximum limit for simultaneous archives. wylieb@google.com clank-tab-dev@google.com (Android only) Records the duration of an archive pass, not including the time it takes to initialize the PersistedTabData (PTD). bjfong@google.com wylieb@google.com clank-tab-dev@google.com Records when a user toggles the settings entry for automatically archiving duplicate tabs on Android. The default state is enabled and is not recorded. This histogram tracks the new state of the toggle and is emitted each time it is changed. True corresponds to enabled and false corresponds to disabled. wylieb@google.com clank-tab-dev@google.com Records when a user toggles the settings entry for automatically deleting inactive tabs on Android. The default state is enabled and is not recorded. This histogram tracks the new state of the toggle and is emitted each time it is changed. True corresponds to enabled and false corresponds to disabled. wylieb@google.com clank-tab-dev@google.com Records when a user selects an archive time preference. ckitagawa@chromium.org clank-tab-dev@google.com Records when a user toggles the settings entry for automatically opening synced tab groups on Android. The default state is enabled and is not recorded. This histogram tracks the new state of the toggle and is emitted each time it is changed. True corresponds to enabled and false corresponds to disabled. wylieb@google.com clank-tab-dev@google.com Records the number of tabs that are currently selected when the close all inactive tabs button is clicked. wylieb@google.com clank-tab-dev@google.com Records the number of tabs that are currently selected when the close menu item is clicked. marq@chromium.org olivierrobin@chromium.org [iOS] The number of tabs opened when the app comes out of the background. With a wider range than Tabs.CountAtResume (100 -> 1M) marq@chromium.org bling-pandamonium@google.com [Android] The number of tabs opened at cold launch. iOS uses Tabs.CountAtStartup2 marq@chromium.org bling-pandamonium@google.com [iOS] The number of tabs opened at cold launch. With a wider range than Tabs.CountAtStartup (100 -> 1M) wylieb@google.com clank-tab-dev@google.com (Android only) Records the duration of an auto-delete pass, including the time it takes to load the PersistedTabData (PTD). ckitagawa@chromium.org clank-tab-dev@google.com [Android] Recorded when a tab's WebContentsState is being modified by freezing and appending to it. Success indicates that the previous state was safely deserialized and could be appended to. Failure indicates that the previous WebContentsState could not be read and will be clobbered. huitingyu@google.com bling-pandamonium@google.com [iOS] The number of invalid duplicated tabs dropped {Occasion}. Note: This tracks invalid web states that share the same identifier. This metric is not to be confused with Tabs.DuplicatesCountAtStartup which counts valid duplicates (i.e. different web states, with different identifiers, but the same URL). huitingyu@google.com bling-pandamonium@google.com [iOS] The number of redundant active tabs restored at cold launch. Note: This metric counts each non-unique tab from the active browser as a redundant tab. E.g. if there are 3 active tabs with the same URL, this metric will represent the amount of total duplicates (i.e. two duplicates). Inactive tabs are not counted towards that metric. kunaldaftari@google.com top-chrome-desktop-ui@google.com Logs whether the window's tab strip is currently in focus mode (focused on a tab group). Recorded every 5 minutes (the heartbeat interval) for each normal browser window. ckitagawa@chromium.org clank-tab-dev@google.com [Android] Recorded when a tab's WebContentsState is being frozen and appended to. Success indicates that the append succeeded. Failure indicates it was not possible to freeze the tab and we had to fallback to a lazy load. huitingyu@google.com bling-pandamonium@google.com [iOS] Records the number of tabs that are considered inactive as per the current tab inactivity threshold. This is recorded at cold launch. wylieb@google.com clank-tab-dev@google.com (Android only) Records the duration of initializing all the PersistedTabData (PTD) from an archive pass. fdoray@chromium.org catan-team@chromium.org The maximum number of tabs that Chrome displays at the same time over the course of a day. Desktop only. NOTE: This metric is asynchronous, the value reported on a given day represents the previous day's observations (which can be from a different build). fdoray@chromium.org catan-team@chromium.org The maximum number of tabs per window that Chrome displays over the course of a day. Desktop Only. NOTE: This metric is asynchronous, the value reported on a given day represents the previous day's observations (which can be from a different build). fdoray@chromium.org catan-team@chromium.org The maximum number of windows existing at the same time over the course of a day. Desktop only. NOTE: This metric is asynchronous, the value reported on a given day represents the previous day's observations (which can be from a different build). skym@chromium.org clank-tab-dev@google.com Records the size of the tab list metadata file that's loaded on tab model creation split out by client type. This is for the regular tab model, not the incognito. Additionally this file may be loaded more times for various things such as clean up and merging, these loads are all ignored. Clients such as headless will still report with their selector type. skym@chromium.org clank-tab-dev@google.com (Android only) Records whether the metadata save was performed synchronously (only the UI thread) or asynchronous (on a background thread). Also useful because it captures the total number of metadata saves. justincohen@google.com bling-fundamentals@google.com Records whether a web state session storage file is missing on session restore. Recorded when the web state is realized. fdoray@chromium.org catan-team@chromium.org The number of tabs total at resume from sleep/hibernate. This is being logged on all desktop platforms. huitingyu@google.com bling-pandamonium@google.com [iOS] Number of tabs older than 21 days. Recorded at cold launch. emshack@chromium.org top-chrome-desktop-ui@google.com On page load, records the time since last active for each tab in the tab strip. emshack@chromium.org top-chrome-desktop-ui@google.com On page load, records the time since creation for each tab in the tab strip. yusufo@chromium.org nyquist@chromium.org dtrainor@chromium.org davidjm@chromium.org FilePersistedTabData storage stores serialized PersistedTabData (metadata persisted across restarts) in a file. This metric records if a delete operation was found to have the file not existing. davidjm@chromium.org dtrainor@chromium.org Records the number of keys that were identified to be orphaned in the LevelDB database for PersistedTabData. PersistedTabData stores Tab data to be persisted across restarts. When a Tab is closed, the data is removed, however, it is possible for data to become orphaned if the app crashes after a Tab is closed and before the cleanup is complete. This metric is recorded in the first callback, OnPerformMaintenance, whereby orphaned keys are identified and before they are deleted. huitingyu@google.com bling-pandamonium@google.com [iOS] The number of pinned tabs opened at cold launch. agale@chromium.org top-chrome-desktop-ui@google.com Counts the number of pinned tabs across each window, reported every 5 minutes. Desktop only. skym@chromium.org ckitagawa@chroimum.org On Android, when a tab becomes dirty, it is queued to be saved to disk. Clients that make multiple modifications in a sequence to the same tab can cause poor performance by triggering a synchronous save from the first modification, and then a second one from the others. This can be manually worked around by notifying the TabStateAttributes, but clients that need this change need to be identified first. This histogram is trying to help identify the frequency that this situation is encountered. This histogram, only on Android, is specifically recorded when we go to queue a tab's data to be saved to persistent storage, and we notice that we're also currently writing the same tab to disk. This is not always a problem, as there could be many pending async writes happening to various tabs, when new fresh modifications come in. The value being recorded is the number of tabs in the save queue in front of the tab being added. If the number is zero, it's very likely because of a client making multiple sequential modifications. On the other hand, a larger number is likely just the same tab being modified asynchronously and the queue is backed up with other changes. ckitagawa@chromium.org fredmello@chromium.org The number of distinct entries of {RecentlyClosedType} that were restored in one Recent Tabs page session on Android. Entries may come from TabRestoreService (Tab, Group, BulkEvent) or from MultiInstanceManager (Window). This is recorded when destroying the Recent Tabs page if any entries of {RecentlyClosedType} type were shown. ckitagawa@chromium.org fredmello@chromium.org The number of distinct entries of {RecentlyClosedType} shown in the Recent Tabs page on Android. Entries may come from TabRestoreService (Tab, Group, BulkEvent) or from MultiInstanceManager (Window). This is recorded when destroying the Recent Tabs page. ckitagawa@chromium.org fredmello@chromium.org Recorded once for each tab closure event processed by HistoricalTabSaverImpl on Android. Enum categories correspond to the the type of closure that was saved to the native TabRestoreService. Tab for single tab, Group for a single tab group and Bulk for a combination of tabs and groups or more than one of either. wylieb@google.com clank-tab-dev@google.com Records the number of tabs that are currently selected when the restore all menu item is clicked. wylieb@google.com clank-tab-dev@google.com Records the number of tabs that are currently selected when the restore menu item is clicked. huitingyu@google.com bling-pandamonium@google.com Recorded on disabling Inactive Tabs (for example in case of an unlaunch). The number of tabs rescued from the orphan inactive tabs browser after the Inactive Tabs experimental flag has been disabled. ckitagawa@chromium.org fredmello@chromium.org [Android] TabState restoration may fail resulting in fallback restoration from the TabStateList or aborting restoration altogether. TabState restoration occurs on startup when restoring tab state from disk or when merging multi-instance modes together. This histogram is emitted when TabState restoration fails to indicate the cause of the failure. sonnyrao@chromium.org jamescook@chromium.org Counts of events from the style of sad tab which has a feedback button as its primary action. Currently, events include being displayed (actually visible in a window), and the actions a user can take on the page. sonnyrao@chromium.org jamescook@chromium.org Counts of events from the style of sad tab which has a reload button as its primary action. Compare to Tabs.SadTab.Feedback.Event. corising@chromium.org top-chrome-desktop-ui@google.com This histogram records the number of tabs that are 'scrubbed' by key press during a given interval of time (i.e. ctrl+tab navigation). For this metric, a tab is considered 'scrubbed' if it was active for less than or equal to a given amount of time. corising@chromium.org top-chrome-desktop-ui@google.com This histogram records the number of tabs that are 'scrubbed' by mouse press during a given interval of time. For this metric, a tab is considered 'scrubbed' if it was active for less than or equal to a given amount of time. afakhry@chromium.org tclaiborne@chromium.org The distance a user multi-finger scrubbed to change tabs. Always positive (ignores left / right). afakhry@chromium.org tclaiborne@chromium.org The duration a user spent doing multi-finger scrubbing to change tabs before a different tab than the currently active one was actually activated. dpenning@chromium.org top-chrome-desktop-ui@google.com The number of selected tabs in a tab strip. Recorded each time the tab selection changes. yusufo@chromium.org ayman@chromium.org davidjm@chromium.org (Android only) Records if we find a BuyableProductAnnotation in the response from our endpoint which provides page annotations to enrich the user experience. The endpoint is called for every Tab when we enter the Tab grid switcher and is cached with a time to live of 1 hour. agale@chromium.org top-chrome-desktop-ui@google.com Records the menu item selected from the split view menu anchored to {SplitViewMenuSource}. madhavpruthi@google.com ckitagawa@chromium.org clank-tab-dev@google.com (Android only) Records the number of {TabType} pinned Tabs loaded on startup per {TabModelSelectorType}. ckitagawa@chromium.org clank-tab-dev@google.com (Android only) Records the realtime duration it took to restore all the tab states per {TabModelSelectorType}. Recorded after tab model selector restoration completes successfully. Android-only. ckitagawa@chromium.org clank-tab-dev@google.com (Android only) Records the average realtime duration it took per-tab to restore all the tab states. Bucketed by {TabModelSelectorType}. Recorded after tab model selector restoration completes successfully. Android-only. davidjm@chromium.org nyquist@chromium.org (Android only) Records the number of {TabType} Tabs loaded on startup. wylieb@google.com clank-tab-dev@google.com (Android only) Records the number of duplicate tabs in the tab metadata found at startup per {TabModelSelectorType}. davidjm@chromium.org nyquist@chromium.org (Android only) Records the number of {TabType} Tabs loaded on startup per {TabModelSelectorType}. wylieb@google.com clank-tab-dev@google.com (Android only) Records the number of duplicate tab URLs found at startup per {TabModelSelectorType}. wylieb@google.com clank-tab-dev@google.com (Android only) Records how many tabs were found in the regular model which have already been archived. Recorded on each declutter pass. wylieb@google.com clank-tab-dev@google.com (Android only) Records how many tabs were archived from the normal tab model selector during an archive pass. wylieb@google.com clank-tab-dev@google.com (Android only) Records how old, in days, a tab is when it's checked for archive eligibility. Recorded at startup when the archived tab model is loaded and at regular intervals after that (default interval is 7d, but is configurable via finch.). Only recorded if tab declutter is enabled. wylieb@google.com clank-tab-dev@google.com (Android only) Records how old, in days, a tab is when it's autodeleted. Age is calculated based on when a tab was archived. wylieb@google.com clank-tab-dev@google.com (Android only) Records how old, in days, a tab is when it's checked for auto-deletion eligibility. Recorded at startup when the archived tab model is loaded and at regular intervals after that (default interval is 7d, but is configurable via finch.). Only recorded if tab declutter is enabled. agale@chromium.org top-chrome-desktop-ui@google.com Counts the number of split tabs across each window, reported every 5 minutes. Desktop only. agale@chromium.org top-chrome-desktop-ui@google.com Counts the number of tabs across each window, reported every 5 minutes. Desktop only. markchang@google.com The number of tabs open in the active window when a load completes. Prior to M-121, this was also recorded when a navigation in a non-tab WebContents (e.g. DevTools, extension popups) happens. Such a navigation would not have affected the recorded value. It would only duplicate a previous recording. dpenning@chromium.org top-chrome-desktop-ui@google.com The number of tabs in the current active group when a load completes. Records 0 if the active tab is not in a group. Prior to M-121, this was also recorded when a navigation in a non-tab WebContents (e.g. DevTools, extension popups) happens. Such a navigation would not have affected the recorded value. It would only duplicate a previous recording. mpearson@chromium.org top-chrome-desktop-ui@google.com sbirch@google.com The number of tabs open in all browsers (counting app-mode windows) when a load completes. This is basically the average number of tabs over time. Prior to M-121, this was also recorded when a navigation in a non-tab WebContents (e.g. DevTools, extension popups) happens. Such a navigation would not have affected the recorded value. It would only duplicate a previous recording. mpearson@chromium.org top-chrome-desktop-ui@google.com The number of tabs open per window (counting app-mode windows) when a load completes. This value will be recorded multiple times per load if more than one window is open. Prior to M-121, this was also recorded when a navigation in a non-tab WebContents (e.g. DevTools, extension popups) happens. Such a navigation would not have affected the recorded value. It would only duplicate a previous recording. fdoray@chromium.org catan-team@chromium.org Counts the number of tabs across all windows, reported every 5 minutes. Desktop only. mfiaz@google.com clank-tab-dev@google.com Records the time elapsed since TabModelOrchestrator initialization until the active {ActiveTabType} tab is loaded. Recorded upon loading the active tab. Android-only. mfiaz@google.com clank-tab-dev@google.com Records the type of authoritative TabPersistentStore. Recorded upon creation of the authoritative TabPersistentStore. Android-only. mfiaz@google.com clank-tab-dev@google.com Records the time elapsed since TabModelOrchestrator initialization until the TabPersistentStore is initialized (metadata read). Recorded when the TabPersistentStore is initialized. Android-only. mfiaz@google.com clank-tab-dev@google.com Records the type of a shadow store. Recorded upon creation of a shadow store. Android-only. mfiaz@google.com clank-tab-dev@google.com Records the time elapsed since TabModelOrchestrator initialization until the tab state is fully loaded. Recorded upon fully loading the tab state. Android-only. davidjm@chromium.org dtrainor@chromium.org nyquist@chromium.org CriticalPersistedTabData is a schema based Tab restoration system which persists Tab metadata such as web contents and time last accessed across restarts. CriticalPersistedTabData will replace legacy hand-written TabState. This metric records how many Tabs are restored using CriticalPersistedTabData, TabState, are re-created, skipped or failed to be restored. As we migrate from TabState to CriticalPersistedTabData it is imperative we can compare the success rate of each system vs. how many Tabs are re-created or failed to be restored. This metric is emitted once for each Tab restoration on startup. ckitagawa@chromium.org dtrainor@chromium.org Records whether the URL in the tab state file and the tab state metadata list match when each tab is restored. Android-only. tluk@chromium.org robliao@chromium.org Tab Search is a feature that allows users to better search for and switch to their desired tabs. The Tab Search UI is shown in a bubble anchored to an element of the UI in the browser window. This metric measures the time it takes for the Tab Search bubble widget to be initialized. tluk@chromium.org robliao@chromium.org Tab Search is a feature that allows users to better search for and switch to their desired tabs. The Tab Search UI is shown in a bubble anchored to an element of the UI in the browser window. This metric is intended to measure the time from when the Tab Search button is pressed to the next visual update of the bubble widget (which may or may not already be visible). It is recorded on successful presentation of the bubble's next compositor frame. We also have metrics measuring time for widget construction. Please refer to Tabs.TabSearch.WindowTimeToShowUncachedWebView and Tabs.TabSearch.WindowTimeToShowCachedWebView. agale@chromium.org top-chrome-desktop-ui@google.com Tracks the action taken by the user within the Tab Search dialog bubble. Recorded when the Tab Search bubble UI is closed. estalin@chromium.org emshack@chromium.org This logs whether the tab search button is pinned to the tab strip. This histogram recorded daily for each profile. kerenzhu@chromium.org romanarora@chromium.org yuhengh@chromium.org tluk@chromium.org robliao@chromium.org The time taken to switch tab. This is measured as the time from when the user clicks a tab in Tab Search to when the browser finishes switching tab. kerenzhu@chromium.org romanarora@chromium.org yuhengh@chromium.org tluk@chromium.org robliao@chromium.org Records whether there's a pending Tabs.TabSearch.Mojo.SwitchToTab measurement when a new measurement is requested. kerenzhu@chromium.org romanarora@chromium.org yuhengh@chromium.org tluk@chromium.org robliao@chromium.org The time taken for Tab Search to update its tab list when the browser's tab strip model changes. This is measured as the time from when the browser emits a notification to when the WebUI updates its state. kerenzhu@chromium.org romanarora@chromium.org yuhengh@chromium.org tluk@chromium.org robliao@chromium.org Records whether there's a pending Tabs.TabSearch.Mojo.TabUpdated measurement when a new measurement is requested. tluk@chromium.org robliao@chromium.org Tab Search is a feature that allows users to better search their browsers for their desired tabs and close any currently open tabs. This records the number of tabs closed from a single instance of the UI (the number of tabs closed from within Tab Search in the time between when the UI is open and when it is closed). tluk@chromium.org robliao@chromium.org Tab Search is a feature that allows users to better search their browsers for their desired tabs. It can be opened and closed. This records the number of tabs there are in the payload Tab Search is sent when it is first opened. tluk@chromium.org robliao@chromium.org Tab Search is a feature that allows users to better search their browsers for their desired tabs. It can be opened and closed. This records the number of windows there are in the payload Tab Search is sent when it is first opened. tluk@chromium.org robliao@chromium.org Tab Search is a feature that allows users to better search for and switch to their desired tabs. The Tab Search UI is shown in a bubble anchored to an element of the UI in the browser window. The bubble can be invoked via a number of different means including mouse click, keyboard navigation, keyboard shortcut or touch gesture. This metric tracks the kind of action the user took to invoke the Tab Search bubble UI. tluk@chromium.org robliao@chromium.org yuhengh@chromium.org romanarora@chromium.org Tab Search is a feature that allows users to better search for and switch to their desired tabs. The Tab Search UI is shown in a bubble anchored to an element of the UI in the browser window. When the WebUIController is first created it waits for the WebUI code in the renderer process to request the creation of the TabSearchPageHandler. This metric tracks the time between when the WebUIController was constructed to when the TabSearchPageHandler begins construction. This metric is emitted right before the TabSearchPageHandler's constructor is called. romanarora@chromium.org robliao@chromium.org tluk@chromium.org yuhengh@chromium.org Tab Search is a feature that allows users to better search for and switch to their desired tabs. The Tab Search UI displays both open and recently closed tabs under different list sections. The recently closed section can be expanded or collapsed by the user by clicking a button. This metric tracks the recently closed section being expandeded or collapsed via the toggle button. romanarora@chromium.org robliao@chromium.org tluk@chromium.org yuhengh@chromium.org Tab Search is a feature that allows users to better search for and switch to their desired tabs. The Tab Search UI displays both open and recently closed tabs under different list sections. The recently closed section can be expanded or collapsed by the user by clicking a button. This metric tracks if the recently closed section is in an expanded or collapsed state at the time of opening the Tab Search dialog. emshack@chromium.org shibalik@chromium.org top-chrome-desktop-ui@google.com Tab Search is a feature that allows users to better search for and switch to their desired tabs. The Tab Search UI is shown in a bubble anchored to an element of the UI in the browser window. This metric measures the length of time the Tab Search bubble widget was open, recorded on close. kerenzhu@chromium.org dayeung@chromium.org tluk@chromium.org robliao@chromium.org This tracks the time between when the Tab Search WebUI bubble widget is first created and when it is first shown to users as reported by the bubble widget's ui compositor. This metric is only logged for the specific warm-up level. The warm-up level indicates the readiness of the browser when it was about to show this WebUI. This metric is emitted when the bubble window is first revealed. agale@chromium.org top-chrome-desktop-ui@google.com Records actions performed by the user within the Tab Search WebUI. Emitted when a user switches to a tab, closes a tab, or opens a recently closed tab/group, from either the filtered (searched) or unfiltered list. tluk@chromium.org robliao@chromium.org yuhengh@chromium.org romanarora@chromium.org Tab Search is a feature that allows users to better search their browsers for their desired tabs and close any currently open tabs. This records the index at which a {Action} has been performed on a tab in Tab Search's tab list in a {State} state. tluk@chromium.org robliao@chromium.org The amount of time between the RenderFrameHost StartProvisionalLoad event and the RenderFrameHost DocumentOnLoadCompleted event for the Tab Search WebUI page. tluk@chromium.org robliao@chromium.org The amount of time between the RenderFrameHost StartProvisionalLoad and DidFinishDocumentLoad events for the Tab Search WebUI page. tluk@chromium.org chrome-cros@chromium.org Tab Search is a feature that allows users to better search their browsers for their desired tabs or recently closed tabs and tab groups. This records whether the user used Tab Search to open a recently closed {Item} from a filtered search results list or the default unfiltered list. yuhengh@chromium.org chrome-cros@chromium.org The time taken to run the search algorithm. The algorithm takes an unfiltered list of items and user search query as inputs, then generate a list of filtered items as output. Recorded after the measurement ends. behery@chromium.org top-chrome-desktop-ui@google.com The time taken to perform a search filter update on the Tab Search WebUI page. This measures the complete duration of the updateFilteredTabs_ pipeline, starting when a tab state update or search query input change is received and ending after the media tabs, open tabs, and recently closed lists are filtered (i.e. the WebUI list component has completed rendering the results in the DOM). Recorded every time the search result list in the Tab Search bubble is updated (e.g., on keystroke, tab update/close, or section expand/collapse). kerenzhu@chromium.org tluk@chromium.org robliao@chromium.org yuhengh@chromium.org kerenzhu@chromium.org The time taken for the WebUI in the renderer to receive the full list of tabs for the current user profile. This is measured as the time from when the data was first requested by the WebUI to when the data was received by the WebUI. This metric is recorded by MetricsReporter. kerenzhu@chromium.org tluk@chromium.org robliao@chromium.org yuhengh@chromium.org kerenzhu@chromium.org Records whether there's a pending Tabs.TabSearch.WebUI.TabListDataReceived2 measurement when a new measurement is requested. tluk@chromium.org robliao@chromium.org Tab Search is a feature that allows users to better search their browsers for and switch to their desired tabs. This records whether the user used Tab Search to switch to a tab from a filtered search results list or the default unfiltered list. yuhengh@chromium.org chrome-cros@chromium.org The time taken between the tab search bubble is open and user switches to a tab or opens a recently closed tab, with or without search query. Recorded after the measurement ends. tluk@chromium.org robliao@chromium.org Tab Search is a feature that allows users to better search their browsers for their desired tabs. It can be opened and closed. This records the amount of time between when a Tab Search bubble is opened and when it is closed. It does so by recording the difference in time between when the the hosting WebUIBubbleDialogView's Widget is first created and when the widget is destroyed. The Tab Search UI is a bubble anchored to an element within a browser window and is closed if the user switches to a tab, presses the escape key or performs an action to return focus to the hosting window. The Tab Search UI bubble will also close if the hosting browser window is closed or crashes. Users may leave the bubble open for long periods of time without directly interacting with the UI which could result in a long tail of displayed durations. tluk@chromium.org robliao@chromium.org yuhengh@chromium.org Tab Search is a feature that allows users to better search for and switch to their desired tabs. The Tab Search UI is shown in a bubble anchored to an element of the UI in the browser window. This tracks the time between when the Tab Search WebUI bubble widget is first created and when it is first shown to users as reported by the bubble widget's ui compositor. This metric is only logged if a previously cached WebView is used for the construction of the bubble widget. This metric is emitted when the bubble window is first revealed. tluk@chromium.org robliao@chromium.org yuhengh@chromium.org Tab Search is a feature that allows users to better search for and switch to their desired tabs. The Tab Search UI is shown in a bubble anchored to an element of the UI in the browser window. This tracks the time between when the Tab Search WebUI bubble widget is first created and when it is first shown to users as reported by the bubble widget's ui compositor. This metric is only logged if a new WebView was created for the construction of the bubble widget. This metric is emitted when the bubble window is first revealed. davidjm@chromium.org clank-tab-dev@google.com TabState (Tab metadata persistence system on Chrome for Android) is being migrated from a hand-written schema to a FlatBuffer based schema. This metric records the number of successful and unsuccessful FlatBuffer deserializations and where known what the reason for unsuccessful deserialization was. yusufo@chromium.org nyquist@chromium.org dtrainor@chromium.org davidjm@chromium.org Time taken to load a TabState file in the event that it exists. davidjm@chromium.org clank-tab-dev@google.com TabState (Tab metadata persistence system on Chrome for Android) has being migrated from a hand-written schema to a FlatBuffer based schema. Part of the cleanup is removing legacy hand-written FlatBuffer files. This metric records if the TabState is fully migrated (FlatBuffer file exists and no legacy file exists), is partially migrated (both FlatBuffer file and legacy file exist) or is unmigrated (only legacy file exists). This metric is recorded when a Tab is restored. davidjm@chromium.org clank-tab-dev@google.com TabState (Tab metadata persistence system on Chrome for Android) is being migrated from a hand-written schema to a FlatBuffer based schema. This metric records the whether a TabState was restored using the FlatBuffer schema, legacy TabState schema (e.g. if a FlatBuffer file hasn't been saved for the Tab yet) or if TabState was failed to be restored (e.g. both the FlatBuffer and legacy TabState file are corrupt). Recorded once per TabState restoration (i.e. once per tab) at cold startup. nyquist@chromium.org dtrainor@chromium.org davidjm@chromium.org Time taken to save a TabState file in the event of a successful save. Includes differentiation between the original legacy based format and FlatBuffer based format. wylieb@google.com clank-tab-dev@google.com Records when a tab is marked as not ready for cleanup because it could possibly be an archived tab. This enum tracks the case specifically for tab state cleanup. mfiaz@google.com clank-tab-dev@google.com [Android] Records the number of tabs we purposefully did not restore during the restoration process. Recorded when the restoration process in TabRestorer has concluded. mfiaz@google.com clank-tab-dev@google.com [Android] Records the decrease in stored tab group count in TabStateStore when shadow store catch-up completes. Recorded when both models have finished loading. mfiaz@google.com clank-tab-dev@google.com [Android] Records the increase in stored tab group count in TabStateStore when shadow store catch-up completes. Recorded when both models have finished loading. mfiaz@google.com clank-tab-dev@google.com [Android] Recorded when the number of tabs restored from the internal tab count tracker is higher than the number of tabs loaded from the database. The value recorded is the difference. mfiaz@google.com clank-tab-dev@google.com [Android] Recorded when the number of tabs loaded from the database is higher than the number of tabs restored from the internal tab count tracker. The value recorded is the difference. skym@chromium.org clank-tab-dev@google.com [Android] Records the duration of reading all tab state information from disk via the TabStateStorageService and creating Java representations of them. This does not include creating full tabs. Recorded when all tab states have been loaded from the service. mfiaz@google.com clank-tab-dev@google.com [Android] Records warnings that occur during TabStateStore tab state data loads. This is logged when there is an error during data loading, and contains context about the error. Recorded when loading the tab state data from the service. mfiaz@google.com clank-tab-dev@google.com [Android] Records the number of warnings that occur when loading TabStateStore tab state data. Recorded after tab state data has been loaded. mfiaz@google.com clank-tab-dev@google.com [Android] Records the decrease in stored pinned tab count in TabStateStore when shadow store catch-up completes. Recorded when both models have finished loading. mfiaz@google.com clank-tab-dev@google.com [Android] Records the increase in stored pinned tab count in TabStateStore when shadow store catch-up completes. Recorded when both models have finished loading. mfiaz@google.com clank-tab-dev@google.com [Android] Records the number of tabs we restored via the Tab List Metadata File's fallback URL during the restoration process. Recorded when the restoration process in TabRestorer has concluded. mfiaz@google.com clank-tab-dev@google.com [Android] Records when the shadow store has caught up to the authoritative store. This is a prerequisite for the shadow store to become the authoritative store during the migration process. skym@chromium.org clank-tab-dev@google.com [Android] Records the delta in tab count between the authoritative and shadow tab models when the authoritative model has more tabs. Recorded when both models have finished loading. This is recorded for the {TabModelOrchestratorType} tab model orchestrator. mfiaz@google.com clank-tab-dev@google.com [Android] Records the tab count when the authoritative and shadow tab models have the same number of tabs. Recorded when both models have finished loading. This is recorded for the {TabModelOrchestratorType} tab model orchestrator. mfiaz@google.com clank-tab-dev@google.com [Android] Records the decrease in stored total tab count in TabStateStore when shadow store catch-up completes. Recorded when both models have finished loading. mfiaz@google.com clank-tab-dev@google.com [Android] Records the increase in stored total tab count in TabStateStore when shadow store catch-up completes. Recorded when both models have finished loading. skym@chromium.org clank-tab-dev@google.com [Android] Records the delta in tab count between the authoritative and shadow tab models when the shadow model has more tabs. Recorded when both models have finished loading. This is recorded for the {TabModelOrchestratorType} tab model orchestrator. skym@chromium.org clank-tab-dev@google.com [Android] Records the time delta when a URL mismatch occurs between the authoritative and shadow tab models, and the authoritative tab is newer. Recorded when both models have finished loading and a URL mismatch is detected. This is recorded for the {TabModelOrchestratorType} tab model orchestrator. skym@chromium.org clank-tab-dev@google.com [Android] Records the time delta when a URL mismatch occurs between the authoritative and shadow tab models, and the shadow tab is newer. Recorded when both models have finished loading and a URL mismatch is detected. This is recorded for the {TabModelOrchestratorType} tab model orchestrator. wylieb@google.com clank-tab-dev@google.com Records when a tab is marked as not ready for cleanup because it could possibly be an archived tab. This enum tracks the case specifically for tab thumbnail cleanup. huitingyu@google.com bling-pandamonium@google.com [iOS] The age of tabs opened at cold launch. The age of a tab is the time elapsed since its creation. huitingyu@google.com bling-pandamonium@google.com [iOS] The number of old/unused tabs opened at cold launch. Inactive tab is a tab that has been not interacted with for more than 7 days. agale@chromium.org top-chrome-desktop-ui@google.com Logs whether the vertical tab strip is collapsed or expanded. This is recorded every 5 minutes (the heartbeat interval) for each window that has the vertical tab strip enabled. Desktop only. charlesmeng@chromium.org top-chrome-desktop-ui@google.com Whether vertical tabs is enabled for a profile. Logged whenever a new user education session starts for each profile in the browser. agale@chromium.org top-chrome-desktop-ui@google.com Records how long the Vertical Tabstrip was expanded for (capped at 1 hour) starting when the expand on hover is triggered. Note this might be different than when the Tabstrip is fully expanded due to animation delays. Recorded when the request is made to collapse the panel. dpenning@chromium.org top-chrome-desktop-ui@google.com The state of vertical tabs across all profiles. Logged by the metric provider for UMA filtering. charlesmeng@chromium.org top-chrome-desktop-ui@google.com When the user finishes dragging to resize the vertical tabstrip, this metric is logged to record the requested size of the tabstrip by the user. fdoray@chromium.org catan-team@chromium.org Counts the number of Chrome windows, reported every 5 minutes. Desktop only. collinbaker@chromium.org top-chrome-desktop-ui@google.com The width of each open browser window, in DIPs, reported every 5 minutes. Desktop only. agale@chromium.org top-chrome-desktop-ui@google.com The width of each open browser window, in DIPs, reported once per UMA log. Desktop only. emshack@chromium.org top-chrome-desktop-ui@google.com Every 5 minutes, records the {MetricType} of duplicate tabs in {WindowType}. If there are 3 tabs with matching URLs, 2 count as duplicates. URL match is determined by {DuplicateType}. Desktop only. dpenning@chromium.org top-chrome-desktop-ui@google.com [Desktop] The size in pixels of the {TabActiveState} tab logged when a tab is added. Used to collect size data for scrolling tabs. dominicaustria@google.com top-chrome-desktop-ui@google.com Recorded periodically every 5 minutes for the horizontal tab strip, indicating whether the unpinned tabs container is overflowing and scrollable. dominicaustria@google.com top-chrome-desktop-ui@google.com Recorded when the unpinned horizontal tab strip is scrolled, indicating whether the scroll was initiated by the scroll buttons or via touchpad / mouse wheel interaction. agale@chromium.org top-chrome-desktop-ui@google.com When a split tab is created, records the method through which it was created. kunaldaftari@google.com top-chrome-desktop-ui@google.com Recorded when a split view is created, capturing the initial layout orientation (stacked or side-by-side). agale@chromium.org top-chrome-desktop-ui@google.com Recorded when a split view is created via a specific source, capturing the initial layout orientation (stacked or side-by-side). agale@chromium.org top-chrome-desktop-ui@google.com When the user reloads a tab using the tab context menu, records the number of tabs being reloaded. atharvmaan@chromium.org top-chrome-desktop-ui@google.com When the user closes tab(s) using hotkey, records the number of tabs being closed. markchang@chromium.org top-chrome-desktop-ui@google.com The keyboard tab switch mode (Standard vs MRU) for each profile. This is recorded once per day for each loaded profile that has at least one tab open. Recorded only for non-Android desktop clients. agale@chromium.org top-chrome-desktop-ui@google.com When the user reloads a tab using the toolbar button, hotkey, or contents context menu, records the number of tabs being reloaded. yuhengh@chromium.org tluk@chromium.org romanarora@chromium.org Tab activation triggered by click or touch on a tab. This is used to measure tab activation count of tab strip vs WebUI tab strip. yusufo@chromium.org wychen@chromium.org This histogram records the number of tabs within the group during page load. If the loading happens in a tab that does not belong to a group, we log 0. Else, we log a positive number >= 2. robliao@chromium.org top-chrome-desktop-ui@google.com The amount of time from receiving a new tab button pressed to creating the elements necessary to represent a new tab. dpenning@chromium.org top-chrome-desktop-ui@google.com The amount of time from cursor entering the tabstrip to first click on a tab to switch. This will exclude some kinds of switching (hotkeys, between windows) where it would be difficult to define a start time. Entering the tabstrip is an approximation which will vary between users, but should still be useful for A/B comparison. agale@chromium.org top-chrome-desktop-ui@google.com The amount of time from cursor entering the vertical tabstrip to first click on a tab to switch. This is only logged when the user is in vertical tabstrip mode. This will exclude some kinds of switching (hotkeys, between windows) where it would be difficult to define a start time. Entering the tabstrip is an approximation which will vary between users, but should still be useful for A/B comparison. estalin@chromium.org top-chrome-desktop-ui@google.com Records the frames per second for the tab strip animation. This is recorded after each tab strip animation is completed when the tab strip expands or collapses. estalin@chromium.org top-chrome-desktop-ui@google.com Records the length of the longest frame in a tab strip animation. This is recorded after each tab strip animation is completed when the tab strip expands or collapses. agale@chromium.org chrome-vertical-tabs-team@google.com Recorded when the user switches to {Mode} tab strip mode. The value indicates the entry point from which the user initiated the switch. kunaldaftari@google.com top-chrome-desktop-ui@google.com The destination of a tab drag operation for either vertical or horizontal tabs. It will either be in the same window, a new window, an existing distinct window, or abandoned. Currently, users cannot drag between tab strips of different types. If that becomes possible, then this metric needs to be updated accordingly to distinguish between those behaviors. kunaldaftari@google.com top-chrome-desktop-ui@google.com The duration of a completed tab drag operation for either vertical or horizontal tabs. Currently, users cannot drag between tab strips of different types. If that becomes possible, then this metric needs to be updated accordingly to distinguish between those behaviors. agale@chromium.org top-chrome-desktop-ui@google.com The pinnedness of dragged tabs in a successful tab drag operation. It tracks whether the dragged tabs are all unpinned, all pinned, or mixed.