sky@chromium.org jam@chromium.org Time (in milliseconds) between when browser launches renderer and renderer message loop starts. iclelland@chromium.org speed-metrics-dev@chromium.org Records the number of 'swaps' performed when inserting a single new Performance Entry into its respective buffer. Recorded each time a new performance entry is inserted into a sorted PerformanceEntryVector. Note that this does not include singleton entries such as NavigationTiming or PaintTiming. yoavweiss@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. yoavweiss@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. yoavweiss@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 The latency improvement provided by the delegated ink trail API, both with and without prediction, in milliseconds. 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. jonross@chromium.org sahir.vellani@microsoft.com The latency improvement provided by predicting extra delegated ink points when using the delegated ink trail API with SkiaRenderer in milliseconds. The improvement is the difference between the timestamp of the final real point and the final predicted point. Part of a series of predicted point experimentation histograms. This experiment predicts {Number} in the future. jonross@chromium.org sahir.vellani@microsoft.com Boolean that indicates whether the prediction is in the same direction as the real trajectory at the same prediction time. True means the direction is not the same (wrong direction). Temporarily not logged in favor of Renderer.DelegatedInkTrail.PredictionExperiment*.WrongDirection since 02-26. Will be reenabled in M95, after experimentation. jonross@chromium.org sahir.vellani@microsoft.com {Direction}shoot distance in pixels between a predicted point and the corresponding interpolated real point that occurred at the prediction time. Temporarily not logged in favor of Renderer.DelegatedInkTrail.PredictionExperiment*.{Direction}Prediction since 02-26. Will be reenabled in M95, after experimentation. jonross@chromium.org sahir.vellani@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. Temporarily not logged in favor of Renderer.DelegatedInkTrail.PredictionExperiment*.{Type}Jitter since 02-26. Will be reenabled in M95, after experimentation. jonross@chromium.org sahir.vellani@microsoft.com Distance in pixels between a predicted point and the corresponding interpolated real point that occurred at the prediction time. The difference between {ScoreType} and Frame{ScoreType} is that the former uses prediction time and the later uses frame time. Part of a series of predicted point experimentation histograms. This experiment predicts {Number} in the future. jonross@chromium.org sahir.vellani@microsoft.com Whether the prediction is in the same direction as the real trajectory at the same prediction time. Part of a series of predicted point experimentation histograms. This experiment predicts {Number} in the future. jonross@chromium.org sahir.vellani@microsoft.com Distance in pixels between a predicted point and the corresponding interpolated real point that occurred at the prediction time. Part of a series of predicted point experimentation histograms. This experiment predicts {Number} in the future. jonross@chromium.org sahir.vellani@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. Part of a series of predicted point experimentation histograms. This experiment predicts {Number} in the future. 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. 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. yoavweiss@chromium.org speed-metrics-dev@chromium.org Boolean indicating that OverfetchedCappedPixels was a positive integer. Reported whenever an image is loaded and painted. yoavweiss@chromium.org speed-metrics-dev@chromium.org Boolean indicating that OverfetchedPixels was a positive integer. Reported whenever an image is loaded and painted. yoavweiss@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. yoavweiss@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. yoavweiss@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. yoavweiss@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 try balancing lines of paragraphs but failed to balance. kojii@chromium.org layout-dev@chromium.org The time spent to optimize line breaks. kojii@chromium.org layout-dev@chromium.org The time spent to try optimizing lines breaks but failed. 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. yoavweiss@chromium.org speed-metrics-dev@chromium.org Counts the number of unused preloads per ResourceType. Warning: an unexpected reorder happened in Apr 2021 (https://crrev.com/c/2798954). Please do not trust older reports. 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 carlscab@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. altimin@chromium.org lpy@chromium.org This boolean keeps track the count of the visibility change of a frame. Recorded every time when the visibility of a frame is changed. 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. altimin@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 or renderer is backgrounded or foregrounded, at most once per second per renderer amortized. ppi@chromium.org Roundtrip times for synchronous IPC calls from the renderer to browser.