sky@chromium.org jam@chromium.org Time (in milliseconds) between when browser launches renderer and renderer message loop starts. iclelland@chromium.org sullivan@chromium.org speed-metrics-dev@chromium.org Time (in milliseconds) from timeOrigin until all the render blocking resources were loaded in pages that have preloaded fonts. The metric will be reported once per page load, once all the render blocking resources and pending preloaded fonts have finished loading. iclelland@chromium.org sullivan@chromium.org speed-metrics-dev@chromium.org Time difference (in milliseconds) between `PreloadedFontLoadTime` and `BlockingResourcesLoadTime`, when the preloaded fonts took longer to load than the render blocking resources, and otherwise 0. This represents the time preloaded fonts would block rendering, if we were to consider them as critical. iclelland@chromium.org sullivan@chromium.org speed-metrics-dev@chromium.org Time (in milliseconds) from timeOrigin until all the preloaded fonts were loaded. The metric will be reported once per page load, once all the render blocking resources and pending preloaded fonts have finished loading. jonross@chromium.org sahir.vellani@microsoft.com gastonr@microsoft.com The latency improvement provided by the delegated ink trail API {Prediction}, in milliseconds {Renderer}. This latency improvement is the difference between the timestamp of the pointerevent provided to the API, and the final point of the trail that is drawn. Points are forwarded from the browser to viz when this API is being used, so viz will have points ahead of what the app provided the API, and they are used to draw the trail. This metric measures how much closer the trail is to the pointer, in time, compared to the last API drawn point. The bigger the histogram's value, the closer Delegated Ink got us to the last pointer position. jonross@chromium.org sahir.vellani@microsoft.com gastonr@microsoft.com {Direction}shoot distance in pixels between a predicted point and the corresponding interpolated real point that occurred at the prediction time. Warning: this histogram was expired from 02-26-2021 to 09-11-2024; data may be missing. jonross@chromium.org sahir.vellani@microsoft.com gastonr@microsoft.com Euclidean distance in pixels between two successive variations of delegated ink trail deltas which are the difference beween a predicted delegated ink point and its corresponding interpolated real position that occurred at {Type} time. Warning: this histogram was expired from 02-26-2021 to 09-11-2024; data may be missing. jonross@chromium.org gastonr@microsoft.com gerchiko@microsoft.com sahir.vellani@microsoft.com Amount of points that are drawn per frame by the Delegated Ink API {Renderer}. This metric can be used as a measurement of how much improvement using the Delegated Ink API by telling us how many points ahead the Delegated Ink API is from the JS API. jonross@chromium.org gastonr@microsoft.com gerchiko@microsoft.com sahir.vellani@microsoft.com Time in milliseconds between the first moment a point is drawn in the screen via the Delegated Ink API using the {Renderer} and the call to updateInkTrailStartPoint is made. This histogram assumes that the point represented by the metadata is painted in the same frame that the metadata is reported in. Note that not all points received as metadata will match a point in the trail. Thus, not all metadata points will generate a histogram fire. jonross@chromium.org gastonr@microsoft.com gerchiko@microsoft.com sahir.vellani@microsoft.com Span of time in milliseconds between the creation of pointer events in the browser process and sending the draw operation to the OS {Renderer}. kojii@chromium.org tkent@chromium.org layout-dev@chromium.org The time spent acquiring the primary font consumed in the main tread before DomContentLoaded. On Windows, this includes IPC roundtrip to browser process and DirectWriteFontProxy and DirectWrite calls. kojii@chromium.org tkent@chromium.org layout-dev@chromium.org The time spent acquiring the primary font consumed in style recalc, in the main tread before DomContentLoaded. On Windows, this includes IPC roundtrip to browser process and DirectWriteFontProxy and DirectWrite calls. kojii@chromium.org tkent@chromium.org layout-dev@chromium.org The time spent acquiring the primary font consumed in the main tread before FCP. On Windows, this includes IPC roundtrip to browser process and DirectWriteFontProxy and DirectWrite calls. kojii@chromium.org tkent@chromium.org layout-dev@chromium.org The time spent acquiring the primary font consumed in style recalc, in the main tread before FCP. On Windows, this includes IPC roundtrip to browser process and DirectWriteFontProxy and DirectWrite calls. kojii@chromium.org tkent@chromium.org layout-dev@chromium.org The time spent finding the system fallback font consumed in the main tread before DomContentLoaded. On Windows, this includes IPC roundtrip to browser process and DirectWriteFontProxy and DirectWrite calls. Warning: This histogram was expired from 2024-09-01 to 2024-11-14. Data may be missing. kojii@chromium.org tkent@chromium.org layout-dev@chromium.org The time spent finding the system fallback font consumed in the main tread before FCP. On Windows, this includes IPC roundtrip to browser process and DirectWriteFontProxy and DirectWrite calls. kerenzhu@chromium.org chrome-views-alerts@google.com The user action taken on the hung renderer dialog. The histogram is recorded when the dialog is accepted, cancelled, or closed by other means (e.g., pressing the escape key). mmocny@chromium.org speed-metrics-dev@chromium.org Boolean indicating that OverfetchedCappedPixels was a positive integer. Reported whenever an image is loaded and painted. mmocny@chromium.org speed-metrics-dev@chromium.org Boolean indicating that OverfetchedPixels was a positive integer. Reported whenever an image is loaded and painted. mmocny@chromium.org speed-metrics-dev@chromium.org Boolean indicating that SizesAttributeMiss was a positive integer. Only set when the sizes attribute is present. Reported whenever an image is loaded and painted. mmocny@chromium.org speed-metrics-dev@chromium.org The amount of HTMLImageElement image pixels squared (width * height) that were fetched by the renderer, but eventually weren't needed, as the layout dimensions of the image corrected to the screen's device pixel ratio (up to a predefined cap) were smaller than the image pixels fetched. Reported whenever an image is loaded and painted. mmocny@chromium.org speed-metrics-dev@chromium.org The amount of HTMLImageElement image pixels squared (width * height) that were fetched by the renderer, but eventually weren't needed, as the layout dimensions of the image corrected to the screen's device pixel ratio were smaller than the image pixels fetched. Reported whenever an image is loaded and painted. mmocny@chromium.org speed-metrics-dev@chromium.org The amount of HTMLImageElement pixels by which the eventual layout width was smaller than the width provided by the sizes attribute. kojii@chromium.org layout-dev@chromium.org The time spent to balance lines of paragraphs. kojii@chromium.org layout-dev@chromium.org The time spent to optimize line breaks. ckitagawa@chromium.org fredmello@chromium.org chrome-fdt@google.com Records the number of milliseconds spent blocking Blink's main thread while capturing the main frame. Reported whenever an image is loaded and painted. ckitagawa@chromium.org fredmello@chromium.org chrome-fdt@google.com Records a boolean indicating whether a capture for the main frame succeeded. ckitagawa@chromium.org fredmello@chromium.org chrome-fdt@google.com Records the number of milliseconds spent blocking Blink's main thread while capturing a subframe. ckitagawa@chromium.org fredmello@chromium.org chrome-fdt@google.com Records a boolean indicating whether a capture for a subframe succeeded. iclelland@chromium.org speed-metrics-dev@chromium.org Counts the number of unused preloads per ResourceType. Renderer.Preload.UnusedResource2.LinkPreload is an equivalent metric that records as enum values. Warning: an unexpected reorder happened in Apr 2021 (https://crrev.com/c/2798954). Please do not trust older reports. sisidovski@chromium.org chrome-loading@google.com Counts the number of unused preloads created {Trigger} per ResourceType. Unlike Renderer.Preload.UnusedResource, this records enum value as it is, not BooleanSuccess. This is recorded after the document completes. sisidovski@chromium.org chrome-loading@google.com Counts the total number of unused preloads. This is recorded after the document completes. fdoray@chromium.org olivierli@chromium.org catan-team@chromium.org The time elapsed between the creation and destruction of a renderer. Recorded for {RendererHostedContentType}. amanvr@chromium.org woa-performance@google.com The histogram is being used to track the number of messages (content::mojom::FrameHost::SubresourceResponseStarted IPCs) being sent by the RenderFrameImpl to notify RenderFrameHostImpl of starting subresource responses, versus the number of times it was deemed unnecessary due to the kReduceSubresourceResponseStartedIPC feature. jam@chromium.org sky@chromium.org The time it takes RenderThreadImpl::Init() to run, recorded for each renderer process. pmonette@chromium.org catan-team@chromium.org Records the reason for which RenderWidgetHostImpl::RendererIsUnresponsive() was called. pmonette@chromium.org catan-team@chromium.org Records the visibility of the WebContents when a renderer is deemed unresponsive (WebContentsImpl::RendererUnresponsive is called). pmonette@chromium.org catan-team@chromium.org Records the priority of the RenderProcessHost at the time a renderer is is deemed unresponsive (WebContentsImpl::RendererUnresponsive is called). Only recorded if the UI element is visible. andresrperez@chromium.org anthonyvd@chromium.org chrome-catan@google.com Records when WebSandboxSupportLinux::GetFallbackFontForCharacter() is called, which uses the FontLoader instead of the Font Manager, and whether a fallback font was found. Recorded once per function call. andresrperez@chromium.org anthonyvd@chromium.org chrome-catan@google.com Records when WebSandboxSupportLinux::GetWebFontRenderStyleForStrike() is called, which uses the FontLoader instead of the Font Manager, and whether style information was found. Recorded once per function call. andresrperez@chromium.org anthonyvd@chromium.org chrome-catan@google.com Records when WebSandboxSupportLinux::MatchFontByPostscriptNameOrFullFontName() is called, which uses the FontLoader instead of the Font Manager, and whether a matching font was found. Recorded once per function call. shaseley@chromium.org speed-metrics-dev@chromium.org The duration that the scheduler is in the discrete input response UseCase. szager@chromium.org paint-dev@chromium.org Time between when a new task is added to a TaskQueue with priority k{Priority}Priority, and when the task begins execution. For delayed (i.e. timer-based) tasks, the initial timestamp is based on the ideal starting time, rather than the time when the event loop notices that the timer has expired. Note: Not recorded on ~5% of Windows machines with low-resolution clocks. anandrv@google.com clank-performance-team@google.com Time spent off-CPU by tasks running on the renderer main thread. Recorded with 0.001 probability when a task scheduled on the main thread finishes running. anandrv@google.com clank-performance-team@google.com Time spent on-CPU by tasks running on the renderer main thread. Recorded with 0.001 probability when a task scheduled on the main thread finishes running. anandrv@google.com clank-performance-team@google.com Records the percentage of wall time spent on-CPU by tasks running on the renderer main thread. Recorded with 0.001 probability when a task scheduled on the main thread finishes running. lizeb@chromium.org shaseley@chromium.org Renderer main thread load (percentage of time spent in tasks), reported in one second chunks. See http://bit.ly/chromium-renderer-main-thread-load-metric for details. This metric is emitted when the renderer main thread task is completed, at most once per second per renderer amortized. lizeb@chromium.org shaseley@chromium.org Renderer main thread load (percentage of time spent in tasks), reported in one second chunks. See http://bit.ly/chromium-renderer-main-thread-load-metric for details. This metric is emitted when the renderer main thread task is completed, at most once per second per renderer amortized. This is only recorded when the renderer was continuously in foreground for the reporting duration.