selya@chromium.org cfredric@chromium.org Records whether storage-access or top-level-storage-access allow access to cookies in a given context. This will be recorded every time cookies are read or set. Subsampled to 1% of all cases. mkwst@chromium.org brandm@microsoft.com cfredric@chromium.org Records if various requests to access storage are allowed or not and if the Storage Access API unblocked the request or not. Recorded whenever a decision to access storage like getting/setting cookies or opening an indexeddb connection is made in CookieSettings. Subsampled to 1% of all cases. cfredric@chromium.org johannhof@chromium.org Records whether or not a document inherited the `has_storage_access` bit from the previous document. Recorded once at document commit, for every document. cfredric@chromium.org johannhof@chromium.org Records whether or not a document was loaded with the `has_storage_access` bit set to true. Recorded once at document commit, for every document. mkwst@chromium.org brandm@microsoft.com Records if a generated grant was implicit or explicit at the time it was created. Warning: this histogram was expired from 2020-11-27 to 08-12-2022; data may be missing. sledoux@chromium.org cfredric@chromium.org Records instances of HTTP responses that include the `Activate-Storage-Access` header with a well-formed value indicating the server would like the response to be loaded with an active storage access permission. Logs whether the header was honored, or the reason for its rejection if it was not. Recorded for each HTTP response received that contains a `Activate-Storage-Access` header with the value of `load`. sledoux@chromium.org cfredric@chromium.org Records whether an HTTP request contains the `Sec-Fetch-Storage-Access` header. If the request did contain the header, it also logs what value of the header was; if the request did not contain the header, it logs why the header was omitted. Recorded whenever an HTTP request is sent. cfredric@chromium.org mreichhoff@chromium.org Records the outcome of a particular Top-Level Storage Access API permission request. Recorded at the time of the request, for every request. cfredric@chromium.org mreichhoff@chromium.org Records invocations of document.requestStorageAccessFor and reasons the request was approved or rejected. Recorded for every call to the function, regardless of outcome. Note that API.StorageAccess.RequestStorageAccess is similar, but for the other variant of this API. huangdarwin@chromium.org src/ui/base/clipboard/OWNERS Counts how often each Clipboard format is read by the platform clipboard. These reads generally imply that an application requested this format after checking that the format is available, but there are some cases where Chrome reads a format to check for existence (outside the ui::Clipboard::ReadAvailableTypes() function). Please prefer interpreting these numbers as relative use changes, as opposed to absolute user usage. dcheng@chromium.org src/ui/base/clipboard/OWNERS Records the time interval between when clipboard data was committed to the clipboard and the same clipboard data was read from the clipboard. The same clipboard data may be read multiple times. Emitted at the moment the clipboard data was read. Currently only implemented for Chrome OS' in-memory clipboard (`ui::ClipboardNonBacked`). huangdarwin@chromium.org src/ui/base/clipboard/OWNERS Counts how often each Clipboard format is written by the platform clipboard. These writes all imply that an application had this format available, and therefore wrote this format. sophiechang@chromium.org src/ui/base/clipboard/OWNERS Records the number of {TextGranularity} in the text that is written to the clipboard. Recorded each time a text copy is written. leimy@chromium.org evanstade@microsoft.com abhishek.shanthkumar@microsoft.com chrome-owp-storage@google.com Logs the total elapsed time between the start of a transaction commit in the backend (browser process), which is when blob writing begins, and when the blobs are reported as successfully written. Not logged for transactions that do not write blobs. leimy@chromium.org evanstade@microsoft.com abhishek.shanthkumar@microsoft.com chrome-owp-storage@google.com Logs the duration of the synchronous work performed in the backend (browser process) for the operation {Operation} on an {IndexedDBBackingStoreType} backing store. Logged once for each successful operation that calls into the backing store (i.e., is non-trivial). leimy@chromium.org evanstade@microsoft.com abhishek.shanthkumar@microsoft.com chrome-owp-storage@google.com Logs the result of each attempt to read the bytes corresponding to a blink.mojom.Blob or storage.mojom.BlobDataItem from an {IndexedDBBackingStoreType} backing store only (i.e., not from pending blobs which are yet to be written to the store). Logged when streaming completes, successfully or otherwise. The source of the bytes may be a file as in the case of LevelDB, or a blob streaming handle as in the case of SQLite. This histogram gates rollout of the SQLite backing store. leimy@chromium.org evanstade@microsoft.com abhishek.shanthkumar@microsoft.com chrome-owp-storage@google.com Logs the result of the operation {Operation} on an {IndexedDBBackingStoreType} backing store. An operation is a group of one or more calls into the backing store performed together (i.e., synchronously). Collectively, these histograms gate rollout of the SQLite backing store. leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com Records the reason that an IndexedDB Mojo request was reported as a bad message. Recorded immediately before the bad message is reported to the Mojo framework. pmonette@chromium.org catan-team@chromium.org Logs the size of the `client_keep_active_remotes_` RemoteSets. Emitted every time a new remote is added. leimy@chromium.org evanstade@microsoft.com abhishek.shanthkumar@microsoft.com chrome-owp-storage@google.com Logs the time it takes to completely shut down `IndexedDBContextImpl`, starting from when it's requested on the UI thread to when the last bucket's destruction is completed. This is only recorded for regular (not incognito) profiles. fdoray@chromium.org catan-team@chromium.org Number of transactions that already exist on the same connection. Recorded everytime a {Mode} transaction is created. Will be used to diagnose crbug.com/381086791. Specifically, we'll assses whether the number of clients who get high values for these histograms is similar to the number of clients who hit transaction timeouts. fdoray@chromium.org catan-team@chromium.org Number of transactions that already exist on the same database. Recorded everytime a {Mode} transaction is created, if the associated database exists. Will be used to diagnose crbug.com/381086791. Specifically, we'll assses whether the number of clients who get high values for these histograms is similar to the number of clients who hit transaction timeouts. leimy@chromium.org evanstade@microsoft.com abhishek.shanthkumar@microsoft.com chrome-owp-storage@google.com The outcome of an IDBFactory::Open request from the browser process's perspective for an {IndexedDBBackingStoreType} backing store. Logged once on receipt of the request and once at the terminal outcome, which is the point after which subsequent results of the request depend on the client's response or on external factors such as the bucket being force-closed. leimy@chromium.org evanstade@microsoft.com abhishek.shanthkumar@microsoft.com chrome-owp-storage@google.com Whether deleting the on-disk data of a bucket with an {IndexedDBBackingStoreType} backing store succeeded. Logged after the attempt to delete on-disk files by a doomed bucket context instance. leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com Windows only. For the longest file name used by the given IndexedDB backing store engine, logs the number of excess characters relative to Windows MAX_PATH, regardless of whether the system in question is actually limited by MAX_PATH (since Chromium does have that limitation). In the vast majority of cases, there should be no overflow, which is logged as 0. This is logged for each engine each time a backing store is created/opened but only when LevelDB is active. Collectively they are intended to measure the impact of the file naming scheme when switching to SQLite. estade@chromium.org chrome-owp-storage@google.com Logs the duration of PartitionedLockManager::GetUnacquirableLocks, but only if it takes over 2ms to execute. This is intended to facilitate tracking down performance issues. See crbug.com/384476946. Warning: this histogram was expired from 2025/04 to 2025/06; data may be missing. leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com Logs the number of queued lock requests that exist in the PartitionedLockManager when GetUnacquirableLocks() takes over 2ms to complete. This is intended to facilitate tracking down performance issues. See crbug.com/384476946 leimy@chromium.org evanstade@microsoft.com abhishek.shanthkumar@microsoft.com chrome-owp-storage@google.com The time between the completion of idle maintenance tasks and the next client-initiated activity in a bucket with an {IndexedDBBackingStoreType} backing store. Logged when the first activity occurs after idle tasks were scheduled and completed. Used to evaluate whether the idle timeout is well-tuned: very small values indicate the timeout may be too short and maintenance is delaying active work. leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com Records the status (including success) when IndexedDB finishes reading a blob-wrapped (large) value. If the read fails, the first value that failed to be unwrapped in a transaction will be logged. This error causes the transaction to abort, preventing further read attempts on other values. This metric is recorded in the renderer process. leimy@chromium.org tamartol@microsoft.com chrome-owp-storage@google.com Records the number of tombstones entries which were found during the LevelDB cleanup task. Recorded when the LevelDbTombstoneSweeper is destroyed. leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com Logs the duration of PartitionedLockManager::LockRequestCancelled, but only if it takes over 2ms to execute. This is intended to facilitate tracking down performance issues. See crbug.com/384476946 leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com Logs the number of queued lock requests that exist in the PartitionedLockManager when LockRequestCancelled() takes over 2ms to complete. This is intended to facilitate tracking down performance issues. See crbug.com/384476946 fdoray@chromium.org catan-team@chromium.org Number of content::indexed_db::Connection objects alive in the browser process when a new Connection is created. Recorded every time a Connection object is created and the number of existing Connection objects is greater than 10k. Will be used to diagnose crbug.com/381086791. fdoray@chromium.org catan-team@chromium.org Number of content::indexed_db::PendingConnection objects alive in the browser process when a new PendingConnection is created. Recorded every time a PendingConnection object is created and the number of existing PendingConnection objects is greater than 10k. Will be used to diagnose crbug.com/381086791. etienneb@chromium.org fdoray@chromium.org catan-team@chromium.org Number of content::indexed_db::PendingConnection objects pending in the ConnectionCoordinator request queue. Will be used to diagnose crbug.com/381086791. fdoray@chromium.org catan-team@chromium.org Number of transactions in a blink::IDBDatabase when a blink::IDBTransaction is created. Recorded every time a blink::IDBTransaction is created and the number of transactions in the blink::IDBDatabase is greater than 10k. Will be used to diagnose crbug.com/381086791. estade@chromium.org chrome-owp-storage@google.com Logs the result of quota checks made by the IndexedDB component on commit of readwrite txns. Warning: this histogram was expired from 2025/04 to 2025/06; data may be missing. estade@chromium.org chrome-owp-storage@google.com Logs the number of transactions remaining on a Connection when Connection::RemoveTransaction() takes over 2ms to complete. This is intended to facilitate tracking down performance issues. See crbug.com/384476946 estade@chromium.org chrome-owp-storage@google.com Logs the duration of Connection::RemoveTransaction(), but only if it takes over 2ms to execute. This is intended to facilitate tracking down performance issues. See crbug.com/384476946 estade@chromium.org chrome-owp-storage@google.com Logs the number of queued lock requests that exist in the PartitionedLockManager when Connection::RemoveTransaction() takes over 2ms to complete. This is intended to facilitate tracking down performance issues. See crbug.com/384476946 leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com Records whether a blob served from IndexedDB's SQLite backing store was read from a legacy file (true) or from the SQLite database itself (false). This helps track the migration progress from legacy file-based blob storage to inline SQLite blob storage. Logged once for each blob that's in a row (IndexedDBValue) that is read from the DB. leimy@chromium.org evanstade@microsoft.com abhishek.shanthkumar@microsoft.com chrome-owp-storage@google.com The percentage of pages in the SQLite database that are on the freelist (unused) at the time the database connection is closed. Logged once per on-disk database close. leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com Logs the result when the SQLite backing store automatically retries opening a DB after the first attempt fails. This only happens for on-disk DBs. leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com Logs the result when the SQLite backing store opens a DB for the sole purpose of reading metadata (i.e. name and version). leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com The compression ratio achieved when putting a value in the SQLite-backed IndexedDB. This is calculated as [compressed size] / [original size]. Depending on this ratio, the value may or may not be stored in its compressed form. leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com The size of the input data, before being compressed, when putting a record in the SQLite-backed IndexedDB, split by whether the data was compressible enough to be stored compressed. This is NOT logged for values where compression was not even attempted. leimy@chromium.org evanstade@microsoft.com chrome-owp-storage@google.com Logs specific events of interest, mostly errors, that occur when using the SQLite backing store for IndexedDB. The specifics of when each are logged are summarized in the enum, but the code is the canonical source of truth. These events are not mutually exclusive; the first event (0) is logged for every time the backing store attempts to open a SQLite database connection. leimy@chromium.org evanstade@microsoft.com abhishek.shanthkumar@microsoft.com chrome-owp-storage@google.com Tracks the vacuum funnel for SQLite-backed IndexedDB databases. An event is logged when vacuuming is attempted on long idle or requested at close. Multiple events may be logged subsequently as the funnel progresses. leimy@chromium.org evanstade@microsoft.com abhishek.shanthkumar@microsoft.com chrome-owp-storage@google.com Records the result of renaming a blob file during IndexedDB backing store migration from LevelDB to SQLite. fdoray@chromium.org catan-team@chromium.org Whether an IndexedDB transaction has a commit pending. Recorded every time the 20 seconds inactivity timeout is hit for a transaction. Will be used to diagnose crbug.com/381086791. {TransactionCount} fdoray@chromium.org catan-team@chromium.org Whether an IndexedDB transaction is aborted. Recorded every time the 20 seconds inactivity timeout is hit for a transaction. Will be used to diagnose crbug.com/381086791. {TransactionCount} fdoray@chromium.org catan-team@chromium.org Whether the connection to which an IndexedDB transaction is associated is connected. Recorded every time the 20 seconds inactivity timeout is hit for a transaction, if it is associated with an existing connection. Will be used to diagnose crbug.com/381086791. {TransactionCount} fdoray@chromium.org catan-team@chromium.org The mode of an IndexedDB transaction. Recorded every time the 20 seconds inactivity timeout is hit for a transaction. Will be used to diagnose crbug.com/381086791. {TransactionCount} fdoray@chromium.org catan-team@chromium.org Number of transactions associated with the same connection as an IndexedDB transaction. Recorded every time the 20 seconds inactivity timeout is hit for a transaction. Will be used to diagnose crbug.com/381086791. We suspect that this can be very high. {TransactionCount} fdoray@chromium.org catan-team@chromium.org Number of transactions associated with the same database as an IndexedDB transaction. Recorded every time the 20 seconds inactivity timeout is hit for a transaction. Will be used to diagnose crbug.com/381086791. We suspect that this can be very high. {TransactionCount} fdoray@chromium.org catan-team@chromium.org Whether a RunTask invocation is queued for the BucketContext. Recorded every time the 20 seconds inactivity timeout is hit for a transaction. Will be used to diagnose crbug.com/381086791. {TransactionCount} estade@chromium.org chrome-owp-storage@google.com Logs the amount of time taken to load a blob from the IDB backing store. This is measured from the renderer, starting when the bytes are requested from the renderer process and finishing when loading is complete i.e. all bytes are available in the renderer process. For simplicity's sake, this is only logged for large values automatically wrapped in blobs, but the results should be applicable to explicit Blobs as well. If the blob bytes need to be unwrapped (decompressed), the time it takes to do so is NOT taken into account. If interested in total time to receive the uncompressed blob bytes, another histogram would need to be added. leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Tracks the success rate of deleting an unused leveldb table backup file. Warning: this histogram was expired from 2025/04 to 2026/08; data may be missing. estade@chromium.org chrome-owp-storage@google.com Logs the success/failure of LevelDB's calls to Sync() (which translates to system calls of fsync(), FlushFileBuffers(), etc). Sync() is only called if the client requests it (e.g. for a strict durability IndexedDB transaction) and after an otherwise successful write. Warning: this histogram was expired from 2024/04 to 2026/01; data is missing. leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Methods where leveldb's Chromium environment has IO errors. {LevelDBEnvTypes} Warning: this histogram was expired from 2026/06 to 2026/08; data may be missing. leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Number of backup files found without corresponding ldb files. As measured by GetChildren when used in LevelDB clients other than IndexedDB. {LevelDBEnvTypes} Warning: this histogram was expired from 2026/06 to 2026/08; data may be missing. leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Delay between the browser process receiving changes and those changes being written to the DB. Warning: this histogram was expired from 2025/03 to 2025/06; data may be missing. arichiv@chromium.org chrome-owp-storage@google.com Emitted when a local StorageArea is shutdown and the access metadata for the associated StorageKey is updated. It's possible to update the access metadata when new data is written to the storage area instead, so this metric does not capture all access metadata updates. Value is true if update succeeded and false if update failed. fergal@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Records the on disk size of the LocalStorage database for a given browser Profile. Recorded once per LocalStorage backend per attempt to open the on-disk database in the Storage process, regardless of open outcome. arichiv@chromium.org chrome-owp-storage@google.com Emitted when the browsing context that loaded the related local storage controller shuts down. One entry is recorded per local storage area. Number of days since a local storage area was modified. Capped at 400 days as areas are not retained past that point. fergal@chromium.org chrome-owp-storage@google.com Size of the HTML5 LocalStorage DB in KB in the renderer-side cache using Mojo implementation. This was expired from 2026-05-31 to 2026-06-08, so data may be missing. fergal@chromium.org chrome-owp-storage@google.com Time (in ms) to load HTML5 LocalStorage into the renderer-side cache using Mojo implementation. This was expired from 2026-05-31 to 2026-06-08, so data may be missing. fergal@chromium.org chrome-owp-storage@google.com Time (in ms) added to loading of LocalStorage into the renderer-side cache used for ablation study purposes. fergal@chromium.org chrome-owp-storage@google.com Time (in ms) to load HTML5 LocalStorage into the renderer-side cache using Mojo implementation, split by size. {LocalStorageSizes} arichiv@chromium.org chrome-owp-storage@google.com Records the amount of orphan (nonce-bound buckets which will never be loaded) storage areas detected on LocalStorageImpl initialization (profile load). Recorded one minute after LocalStorageImpl initialization to ensure any restored tabs have loaded. See crbug.com/353555346 for more info. leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com The renderer side cache hit rate metrics for new HTML5 LocalStorage DB opened. Warning: this histogram was expired from M78 to M92 and from 2026-03-08 to 2026-07-24; data may be missing. arichiv@chromium.org chrome-owp-storage@google.com Records the amount of stale (400 days since last access or write) storage areas deleted on LocalStorageImpl initialization (profile load). Emitted after successful attempt to delete stale storage areas. See crbug.com/40281870 for more info. arichiv@chromium.org chrome-owp-storage@google.com Records the success of clearing stale (400 days since last access or write) storage areas on LocalStorageImpl initialization (profile load). Emitted after attempt to delete stale storage areas occurs. See crbug.com/40281870 for more info. leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Methods where leveldb's Mojo environment has IO errors. This histogram has expired between M87-106. Warning: this histogram was expired from 2026/06 to 2026/08; data may be missing. estade@chromium.org chrome-owp-storage@google.com Recorded when FileReaderLoader.FailureType2 records a data pipe not readable error. This is the specific type of Mojo error. Warning: this histogram was expired from 2025/02 to 2025/06 and from 2026/07 to 2026/08; data may be missing. estade@chromium.org chrome-owp-storage@google.com Recorded when an error occurs in the FileReaderLoader, which is used to load blobs in the Renderer. FileReaderUser is mostly used for Javascript's 'FileReader', but can also be used to read blobs for the IndexedDB renderer-side implementation. For the read error category, see Storage.Blob.FileReaderLoader.ReadError for a breakdown of the specific read error reasons. Warning: this histogram was expired from 2026/05 to 2026/08; data may be missing. estade@chromium.org chrome-owp-storage@google.com The error code reported by the blob system while trying to read a blob in the FileReaderLoader. Warning: this histogram was expired from 2026/05 to 2026/08; data may be missing. estade@chromium.org chrome-owp-storage@google.com Counts the number of storage buckets in existence for a StorageKey when a new one is created (including the new one). This is intended to give an idea of the number of buckets individual apps use. Note: the count in histogram bucket 1 correlates to the total number of sites that use the buckets API (per Chrome client). The count in histogram bucket N, divided by the size of the bucket, correlates to the number of sites for that Chrome client which use at least that many buckets. Warning: this histogram was expired from 2025/04 to 2025/06; data may be missing. estade@chromium.org chrome-owp-storage@google.com The requested durability for a bucket when it is open()ed. Warning: this histogram was expired from 2025/04 to 2025/06; data may be missing. estade@chromium.org chrome-owp-storage@google.com The expiration time for a bucket, in minutes, if provided when it is open()ed. If not provided, the underflow bucket is used. Warning: this histogram was expired from 2025/04 to 2025/06; data may be missing. estade@chromium.org chrome-owp-storage@google.com The requested persistence for a bucket when it is open()ed. Warning: this histogram was expired from 2025/04 to 2025/06; data may be missing. estade@chromium.org chrome-owp-storage@google.com The requested quota for a bucket, in kB, if provided. If not provided, the underflow bucket is used. Logged when the bucket is open()ed. Warning: this histogram was expired from 2025/04 to 2025/06; data may be missing. estade@chromium.org chrome-owp-storage@google.com A Clear-Site-Data response header was seen with the given values. sisidovski@chromium.org chrome-loading@google.com Records the size of the Declarative Performance Observer SQLite database file on disk. Recorded during database initialization. sisidovski@chromium.org chrome-loading@google.com Records the number of early failure reports evicted in a single operation to satisfy storage quota constraints. Recorded whenever eviction completes. sisidovski@chromium.org chrome-loading@google.com Records the number of stored early failure reports deleted during database initialization because they exceeded the TTL limit. Recorded only when the number of expired reports is greater than zero. sisidovski@chromium.org chrome-loading@google.com Records the outcome of reading stored early failure reports from the Declarative Performance Observer SQLite database. Recorded on the database sequence whenever early failure reports are taken for delivery. sisidovski@chromium.org chrome-loading@google.com Records the total number of unique origins with active early-failure policies tracked in the SQLite database. Recorded during database initialization. sisidovski@chromium.org chrome-loading@google.com Records the total number of early failure reports stored in the SQLite database. Recorded during database initialization. sisidovski@chromium.org chrome-loading@google.com Records the outcome of attempting to serialize and store an early failure report in the Declarative Performance Observer SQLite database. Recorded on the database sequence for each write attempt. cammie@chromium.org leimy@chromium.org chrome-owp-storage@google.com Whether the database files still exist for {Api} on profile startup, so they are deleted subsequently. if they were no longer present. fergal@chromium.org leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com The size of the input value, before compression, when writing a key-value pair in the DomStorage SQLite backend. Split by whether the value was compressible enough to be stored compressed. Only logged for values at or above the minimum compression threshold. fergal@chromium.org leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com The compression ratio achieved when writing a value in the DomStorage SQLite backend. Calculated as [compressed size] / [original size] * 100. Depending on this ratio, the value may or may not be stored in its compressed form. Only logged for values at or above the minimum compression threshold. mych@chromium.org src/content/browser/file_system_access/OWNERS Records whether a site attempted to observe a symlink or a junction using the File System Observer API. Recorded on every observe() call after validating the handle and ensuring that read permissions on the handle are granted. Only recorded when observing a handle in the LocalFileSystem. leimy@chromium.org src/content/browser/file_system_access/OWNERS Logs the time it takes to execute ChromeFileSystemAccessPermissionContext::ConfirmSensitiveEntryAccess(). This metric will be used to estimate the impact of the performance improvements made to the blocklists check within the method. mych@chromium.org src/content/browser/file_system_access/OWNERS Records if content::FilePathWatcher sends an error to its callback and how it failed. Recorded on every error sent to the callback. mych@chromium.org src/content/browser/file_system_access/OWNERS Records the high water mark of inotify watches used in a FilePathWatcher on Linux. Recorded when the FilePathWatcher is destroyed. mych@chromium.org src/content/browser/file_system_access/OWNERS Records the number of times an observer's callback is triggered per observation in a one second window. Recorded one second after a callback has been triggered when there is no ongoing window. mych@chromium.org src/content/browser/file_system_access/OWNERS Records the high water mark of OS-specific observer resource usage for a given StorageKey. Recorded when FileSystemAccessObserverQuotaManager is destroyed. mych@chromium.org src/content/browser/file_system_access/OWNERS Records whether FileSystemObserver usage change caused quota to be exceeded. Recorded when FileSystemAccessObserverQuotaManager is destroyed. mych@chromium.org src/content/browser/file_system_access/OWNERS Records the percentage ratio of high water mark of OS-specific observer resource usage over the total available quota for a given StorageKey. Recorded when FileSystemAccessObserverQuotaManager is destroyed. mych@chromium.org src/content/browser/file_system_access/OWNERS The result of a user interaction with the File System Access Persistent Permissions restore prompt UI. mych@chromium.org src/content/browser/file_system_access/OWNERS The result of a user interaction with the File System Access Persistent Permissions Page Info UI checkbox toggle option to enable or disable Extended Permissions for a given origin. mych@chromium.org src/content/browser/file_system_access/OWNERS Records if content::FilePathWatcher::WatchWitchChangeInfo succeeds and if it doesn't, how it fails. Recorded for every call. mych@chromium.org src/content/browser/file_system_access/OWNERS The result of an attempt to request permission to a file or directory via the File System Access API. caraitto@chromium.org pauljensen@chromium.org Records the size of each ad component renderURL in bytes. Recorded for each ad component, each time an interest group is successfully joined. caraitto@chromium.org pauljensen@chromium.org Records the percentage ratio of compressed size divided by uncompressed size of the AdsProto, times 100. Recorded each time the AdProto is compressed, including both during interest group insertion, and database migration from older uncompressed versions, unless uncompressed size is 0. Includes both ads and ad components. caraitto@chromium.org pauljensen@chromium.org Records the time taken to compress the ad proto. Recorded each time the AdProto is compressed, including both during interest group insertion, and database migration from older uncompressed versions. Includes both ads and ad components. caraitto@chromium.org pauljensen@chromium.org Records the outcome of interest group AdProto decompression, recorded on each decompression attempt. Includes both ads and ad components. caraitto@chromium.org pauljensen@chromium.org Records the outcome of interest group AdProto decompression, recorded on each successful decompression attempt. Includes both ads and ad components. caraitto@chromium.org pauljensen@chromium.org Records the time taken to deserialize the ad proto. Recorded each time the AdProto is deserialized. Includes both ads and ad components. caraitto@chromium.org pauljensen@chromium.org Records the time taken to serialize the ad proto. Recorded each time the AdProto is serialized, including both during interest group insertion, and database migration. Includes both ads and ad components. caraitto@chromium.org pauljensen@chromium.org Records the size of the compressed AdProto, recorded each time the AdProto is compressed, including both during interest group insertion, and database migration from older uncompressed versions, even if the uncompressed size is 0. Includes both ads and ad components. caraitto@chromium.org pauljensen@chromium.org Records the size of the uncompressed AdProto, recorded each time the AdProto is compressed, including both during interest group insertion, and database migration from older uncompressed versions, even if the uncompressed size is 0. Includes both ads and ad components. caraitto@chromium.org pauljensen@chromium.org Records the size of each ad renderURL in bytes. Recorded for each ad, each time an interest group is successfully joined. behamilton@google.com pauljensen@chromium.org Records the number of database errors that occur when accessing interest group storage. behamilton@google.com pauljensen@chromium.org Records the time spent performing database maintenance on the interest group storage. Recorded when maintenance is run (approximately once an hour). Note that clients without high-resolution clocks will report 0 for very short times. behamilton@google.com pauljensen@chromium.org Records the size of the InterestGroup database. Collected prior to database maintenance. caraitto@chromium.org pauljensen@chromium.org privacy-sandbox-dev@chromium.org Tracks whether or not it was necessary to create a new opaque origin to use as the top-frame origin for the call to `ContentBrowserClient::IsInterestGroupAPIAllowed()` when storing headers received from the network service. Recorded every time this check was made. NOTE: This histogram doesn't apply to normal joins, updates, auctions, etc. -- it just applies to checks applied after receiving headers from the network service. caraitto@chromium.org pauljensen@chromium.org Records the result of database initialization, every time initialization is attempted. caraitto@chromium.org pauljensen@chromium.org Records the result of JSON deserialization, every time it is attempted. caraitto@chromium.org pauljensen@chromium.org Records the result of JSON serialization, every time it is attempted. orrb@chromium.org privacy-sandbox-dev@chromium.org The fraction of keys that need to be fetched for a particular interest group that are available from the on-device cache of keys retained from prior requests to the k-anonymity server. As with other percent metrics, this is recorded as an integer of 0-100. Recorded immediately after the cache is checked for k-anonymity keys prior to attempting a fetch from the k-anonymity server, and only when the cache is checked, i.e. not when the `kFledgeCacheKAnonHashedKeys` feature is disabled. See https://github.com/WICG/turtledove/blob/main/FLEDGE.md for the latest version of the FLEDGE explainer. caraitto@chromium.org pauljensen@chromium.org Records the number of ads components per interest group. Recorded each time an interest group is successfully joined when a (potentially-empty) ad components array was passed to joinAdInterestGroup(). caraitto@chromium.org pauljensen@chromium.org Records the number of ads per interest group. Recorded each time an interest group is successfully joined when a (potentially-empty) ads array was passed to joinAdInterestGroup(). behamilton@google.com pauljensen@chromium.org Records the number of interest groups loaded for a single group owner when running an ad auction. Recorded for each owner involved in a running ad auction. caraitto@chromium.org pauljensen@chromium.org privacy-sandbox-dev@chromium.org Records an estimate of the number of prevWins entries per interest group, reported each time it is loaded from the database, both for on-device and B&A auctions. caraitto@chromium.org pauljensen@chromium.org Records the result of {Type} Proto deserialization, every time it is attempted. caraitto@chromium.org pauljensen@chromium.org Records the result of {Type} Proto serialization, every time it is attempted. caraitto@chromium.org pauljensen@chromium.org Records the {Version} version number of database upgrades that {Outcome}, recorded each time the database upgrade has a "{Outcome}" outcome. caraitto@chromium.org pauljensen@chromium.org Records the result of the vacuum operation, every time it is attempted. leimy@chromium.org fergal@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Records whether the session storage database was cleared during storage partition initialization. True means the database was destroyed and recreated because no session restore was needed. Emitted once per storage partition during initialization. fergal@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Records the on disk size of the SessionStorage database for a given browser Profile. Recorded once per SessionStorage backend per attempt to open the on-disk database in the Storage process, regardless of open outcome. leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com The renderer side cache hit rate metrics for new HTML5 SessionStorage DB opened. This histogram has expired between M97-106. elabadysayed@chromium.org src/content/browser/OWNERS Records the synchronous duration of StoragePartitionImpl::Initialize() on the UI thread across all //content embedders. Emitted once every time a storage partition is initialized. elabadysayed@chromium.org src/content/browser/OWNERS Records the synchronous duration of {Step} inside StoragePartitionImpl::Initialize() on the UI thread. Note: The order and grouping of initialization steps within StoragePartitionImpl::Initialize() are implementation details and are not guaranteed to remain stable across Chromium releases. If new features are added or steps are reordered, data continuity across versions will be broken. Consequently, this metric should only be considered for comparisons within the exact same browser version. elabadysayed@chromium.org src/content/browser/OWNERS Records the synchronous duration of StoragePartitionImplMap::Get() on the UI thread across all //content embedders. Emitted once every time a storage partition is retrieved or created in the map. fergal@chromium.org leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Records the number of consecutive commit errors that accumulated before the error counter was reset in {DomStorageType}. Emitted whenever the counter is reset from a non-zero value, whether due to a subsequent successful commit or an attempt to recover the database. These errors represent commits whose data was silently lost without retry. The .OnDiskExperimental suffix identifies databases in the SQLite rollout experiment (treatment or control group). Its absence identifies databases not participating in the experiment. leimy@chromium.org fergal@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Records the SQLite result code reported via the {DomStorageType} database's error callback whenever a SQLite operation fails. Recorded once per error. leimy@chromium.org fergal@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Records the duration of {Operation} operations in {DomStorageType} using {DomStorageBackingStoreLifetime} database. Measured on the DB sequence around the actual database call, which excludes task-queue delays. This helps compare latency between the LevelDB and SQLite backends. fergal@chromium.org leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Records whether the database recovery attempt for {DomStorageType} succeeded when the database was originally in-memory. True means recovery succeeded (re-opened successfully), false means we gave up after attempting and failing to reopen. {DomStorageRecoveryReason} indicates what initiated the recovery. fergal@chromium.org leimy@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Records the outcome of a database recovery attempt for {DomStorageType} that started on disk. Emitted once per recovery cycle when reaching a terminal state (successful reconnection or gave up). To track ongoing instability, it is also emitted each time the commit-error threshold is exceeded after a prior recovery attempt, and when post-recovery errors occur but resolve via a successful commit. The {DomStorageRecoveryReason} suffix indicates what initiated the recovery. The .OnDiskExperimental suffix identifies databases in the SQLite rollout experiment (treatment or control group). Its absence identifies databases not participating in the experiment. leimy@chromium.org stevebe@microsoft.com chrome-owp-storage@google.com Records data loss that occurs when browser shutdown discards pending changes. leimy@chromium.org fergal@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Reclaimable space in the on-disk {DomStorageType} SQLite database, computed as the freelist page count times the page size and sampled once when the database is opened. This is the space a vacuum would return to the file system. Only recorded for on-disk databases. leimy@chromium.org fergal@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Freelist pages as a percentage of total pages in the on-disk {DomStorageType} SQLite database, sampled once when the database is opened. Indicates how fragmented the database is. Only recorded for on-disk databases. leimy@chromium.org fergal@chromium.org rahsin@microsoft.com chrome-owp-storage@google.com Records the database status result for {Operation} operations in {DomStorageType} using {DomStorageBackingStoreLifetime} database. This helps track the success and failure rates of database operations calculated using the OK and non-OK results. The non-OK results are not comparable across backends. For OpenDatabase, any non-OK result leads to the database getting clobbered.