tools/metrics/histograms/metadata/renderer/histograms.xml

<!--
Copyright 2020 The Chromium Authors
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->

<!--
This file is used to generate a comprehensive list of Renderer histograms
along with a detailed description for each histogram.

For best practices on writing histogram descriptions, see
https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histograms/README.md

Please follow the instructions in the OWNERS file in this directory to find a
reviewer. If no OWNERS file exists, please consider signing up at
go/reviewing-metrics (Googlers only), as all subdirectories are expected to
have an OWNERS file. As a last resort you can send the CL to
chromium-metrics-reviews@google.com.
-->

<histogram-configuration>

<histograms>

<variants name="RendererHostedContentType">
  <variant name="" summary="all renderers"/>
  <variant name=".Empty"
      summary="renderers that never hosted a frame or a worker"/>
  <variant name=".Extension"
      summary="renderers that hosted an extension background page"/>
  <variant name=".MainFrame"
      summary="renderers that hosted a navigated main frame"/>
  <variant name=".Speculative"
      summary="speculative renderers, i.e. renderers that hosted frames but
               in which no navigation commit occured"/>
  <variant name=".Subframe_Ad"
      summary="renderers that hosted a navigated subframe (tagged as an ad),
               but no main frame"/>
  <variant name=".Subframe_NoAd"
      summary="renderers that hosted a navigated subframe (not tagged as an
               ad), but no main frame"/>
  <variant name=".Worker"
      summary="renderers that hosted a worker (service, dedicated or shared),
               but no navigated frame"/>
</variants>

<histogram name="Renderer.BrowserLaunchToRunLoopStart" units="ms"
    expires_after="2023-10-08">
  <owner>sky@chromium.org</owner>
  <owner>jam@chromium.org</owner>
  <summary>
    Time (in milliseconds) between when browser launches renderer and renderer
    message loop starts.
  </summary>
</histogram>

<histogram
    name="Renderer.Core.Timing.Performance.SwapsPerPerformanceEntryInsertion"
    units="swaps" expires_after="2023-05-01">
  <owner>iclelland@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.CriticalFonts.BlockingResourcesLoadTime" units="ms"
    expires_after="2023-09-03">
  <owner>yoavweiss@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.CriticalFonts.CriticalFontDelay" units="ms"
    expires_after="2023-09-03">
  <owner>yoavweiss@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.CriticalFonts.PreloadedFontsLoadTime" units="ms"
    expires_after="2023-09-03">
  <owner>yoavweiss@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram
    name="Renderer.DelegatedInkTrail.LatencyImprovement.{Renderer}.{Prediction}"
    units="ms" expires_after="2024-02-01">
  <owner>jonross@chromium.org</owner>
  <owner>sahir.vellani@microsoft.com</owner>
  <summary>
    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.
  </summary>
  <token key="Renderer">
    <variant name="Skia"/>
  </token>
  <token key="Prediction">
    <variant name="WithoutPrediction"/>
    <variant name="WithPrediction"/>
  </token>
</histogram>

<histogram
    name="Renderer.DelegatedInkTrail.LatencyImprovementWithPrediction.Experiment{Number}"
    units="ms" expires_after="2024-02-01">
  <owner>jonross@chromium.org</owner>
  <owner>sahir.vellani@microsoft.com</owner>
  <summary>
    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.
  </summary>
  <token key="Number">
    <variant name="0" summary="1 predicted point, 12ms"/>
    <variant name="1" summary="2 predicted points, 6ms and 12ms"/>
    <variant name="2" summary="1 predicted point, 6ms"/>
    <variant name="3" summary="2 predicted points, 3ms and 6ms"/>
  </token>
</histogram>

<histogram name="Renderer.DelegatedInkTrail.Prediction.WrongDirection"
    enum="BooleanDirection" expires_after="2024-02-01">
  <owner>jonross@chromium.org</owner>
  <owner>sahir.vellani@microsoft.com</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.DelegatedInkTrail.Prediction.{Direction}Prediction"
    units="pixels" expires_after="2024-02-01">
  <owner>jonross@chromium.org</owner>
  <owner>sahir.vellani@microsoft.com</owner>
  <summary>
    {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.
  </summary>
  <token key="Direction">
    <variant name="Over"/>
    <variant name="Under"/>
  </token>
</histogram>

<histogram name="Renderer.DelegatedInkTrail.Prediction.{Type}Jitter"
    units="pixels" expires_after="2024-02-01">
  <owner>jonross@chromium.org</owner>
  <owner>sahir.vellani@microsoft.com</owner>
  <summary>
    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.
  </summary>
  <token key="Type">
    <variant name="Prediction" summary="prediction"/>
    <variant name="Visual" summary="frame"/>
  </token>
</histogram>

<histogram
    name="Renderer.DelegatedInkTrail.PredictionExperiment{Number}.Frame{ScoreType}"
    units="pixels" expires_after="2024-02-01">
  <owner>jonross@chromium.org</owner>
  <owner>sahir.vellani@microsoft.com</owner>
  <summary>
    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.
  </summary>
  <token key="Number">
    <variant name="0" summary="1 predicted point, 12ms"/>
    <variant name="1" summary="2 predicted points, 6ms and 12ms"/>
    <variant name="2" summary="1 predicted point, 6ms"/>
    <variant name="3" summary="2 predicted points, 3ms and 6ms"/>
  </token>
  <token key="ScoreType">
    <variant name="OverPrediction" summary="Positive score values"/>
    <variant name="PredictionScore" summary="Score abolute value"/>
    <variant name="UnderPrediction" summary="Negative score values"/>
  </token>
</histogram>

<histogram
    name="Renderer.DelegatedInkTrail.PredictionExperiment{Number}.WrongDirection"
    enum="BooleanDirection" expires_after="2024-02-01">
  <owner>jonross@chromium.org</owner>
  <owner>sahir.vellani@microsoft.com</owner>
  <summary>
    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.
  </summary>
  <token key="Number">
    <variant name="0" summary="1 predicted point, 12ms"/>
    <variant name="1" summary="2 predicted points, 6ms and 12ms"/>
    <variant name="2" summary="1 predicted point, 6ms"/>
    <variant name="3" summary="2 predicted points, 3ms and 6ms"/>
  </token>
</histogram>

<histogram
    name="Renderer.DelegatedInkTrail.PredictionExperiment{Number}.{ScoreType}"
    units="pixels" expires_after="2024-02-01">
  <owner>jonross@chromium.org</owner>
  <owner>sahir.vellani@microsoft.com</owner>
  <summary>
    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.
  </summary>
  <token key="Number">
    <variant name="0" summary="1 predicted point, 12ms"/>
    <variant name="1" summary="2 predicted points, 6ms and 12ms"/>
    <variant name="2" summary="1 predicted point, 6ms"/>
    <variant name="3" summary="2 predicted points, 3ms and 6ms"/>
  </token>
  <token key="ScoreType">
    <variant name="OverPrediction" summary="Positive score values"/>
    <variant name="PredictionScore" summary="Score abolute value"/>
    <variant name="UnderPrediction" summary="Negative score values"/>
  </token>
</histogram>

<histogram
    name="Renderer.DelegatedInkTrail.PredictionExperiment{Number}.{Type}Jitter"
    units="pixels" expires_after="2024-02-01">
  <owner>jonross@chromium.org</owner>
  <owner>sahir.vellani@microsoft.com</owner>
  <summary>
    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.
  </summary>
  <token key="Number">
    <variant name="0" summary="1 predicted point, 12ms"/>
    <variant name="1" summary="2 predicted points, 6ms and 12ms"/>
    <variant name="2" summary="1 predicted point, 6ms"/>
    <variant name="3" summary="2 predicted points, 3ms and 6ms"/>
  </token>
  <token key="Type">
    <variant name="Prediction" summary="prediction"/>
    <variant name="Visual" summary="frame"/>
  </token>
</histogram>

<histogram name="Renderer.Font.PrimaryFont.DomContentLoaded" units="ms"
    expires_after="2023-10-08">
  <owner>kojii@chromium.org</owner>
  <owner>tkent@chromium.org</owner>
  <owner>yosin@chromium.org</owner>
  <owner>layout-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.Font.PrimaryFont.DomContentLoaded.Style" units="ms"
    expires_after="2023-08-20">
  <owner>kojii@chromium.org</owner>
  <owner>tkent@chromium.org</owner>
  <owner>yosin@chromium.org</owner>
  <owner>layout-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.Font.PrimaryFont.FCP" units="ms"
    expires_after="2023-10-22">
  <owner>kojii@chromium.org</owner>
  <owner>tkent@chromium.org</owner>
  <owner>yosin@chromium.org</owner>
  <owner>layout-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.Font.PrimaryFont.FCP.Style" units="ms"
    expires_after="2023-06-18">
  <owner>kojii@chromium.org</owner>
  <owner>tkent@chromium.org</owner>
  <owner>yosin@chromium.org</owner>
  <owner>layout-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.Font.SystemFallback.DomContentLoaded" units="ms"
    expires_after="2023-08-08">
  <owner>kojii@chromium.org</owner>
  <owner>tkent@chromium.org</owner>
  <owner>yosin@chromium.org</owner>
  <owner>layout-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.Font.SystemFallback.FCP" units="ms"
    expires_after="2023-06-25">
  <owner>kojii@chromium.org</owner>
  <owner>tkent@chromium.org</owner>
  <owner>yosin@chromium.org</owner>
  <owner>layout-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.Images.HasOverfetchedCappedPixels" enum="Boolean"
    expires_after="2023-09-03">
  <owner>yoavweiss@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    Boolean indicating that OverfetchedCappedPixels was a positive integer.
    Reported whenever an image is loaded and painted.
  </summary>
</histogram>

<histogram name="Renderer.Images.HasOverfetchedPixels" enum="Boolean"
    expires_after="2023-09-03">
  <owner>yoavweiss@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    Boolean indicating that OverfetchedPixels was a positive integer. Reported
    whenever an image is loaded and painted.
  </summary>
</histogram>

<histogram name="Renderer.Images.HasSizesAttributeMiss" enum="Boolean"
    expires_after="2023-09-03">
  <owner>yoavweiss@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    Boolean indicating that SizesAttributeMiss was a positive integer. Only set
    when the sizes attribute is present. Reported whenever an image is loaded
    and painted.
  </summary>
</histogram>

<histogram name="Renderer.Images.OverfetchedCappedPixels" units="px^2"
    expires_after="2023-09-03">
  <owner>yoavweiss@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.Images.OverfetchedPixels" units="px^2"
    expires_after="2023-09-03">
  <owner>yoavweiss@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.Images.SizesAttributeMiss" units="px"
    expires_after="2023-09-03">
  <owner>yoavweiss@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    The amount of HTMLImageElement pixels by which the eventual layout width was
    smaller than the width provided by the sizes attribute.
  </summary>
</histogram>

<histogram name="Renderer.Layout.TextWrapBalance" units="ms"
    expires_after="2023-10-20">
  <owner>kojii@chromium.org</owner>
  <owner>layout-dev@chromium.org</owner>
  <summary>The time spent to balance lines of paragraphs.</summary>
</histogram>

<histogram name="Renderer.Layout.TextWrapBalance.Fail" units="ms"
    expires_after="2023-10-20">
  <owner>kojii@chromium.org</owner>
  <owner>layout-dev@chromium.org</owner>
  <summary>
    The time spent to try balancing lines of paragraphs but failed to balance.
  </summary>
</histogram>

<histogram name="Renderer.PaintPreview.Capture.MainFrameBlinkCaptureDuration"
    units="ms" expires_after="2023-09-10">
  <owner>ckitagawa@chromium.org</owner>
  <owner>fredmello@chromium.org</owner>
  <owner>chrome-fdt@google.com</owner>
  <summary>
    Records the number of milliseconds spent blocking Blink's main thread while
    capturing the main frame. Reported whenever an image is loaded and painted.
  </summary>
</histogram>

<histogram name="Renderer.PaintPreview.Capture.MainFrameSuccess"
    enum="BooleanSuccess" expires_after="2023-05-27">
  <owner>ckitagawa@chromium.org</owner>
  <owner>fredmello@chromium.org</owner>
  <owner>chrome-fdt@google.com</owner>
  <summary>
    Records a boolean indicating whether a capture for the main frame succeeded.
  </summary>
</histogram>

<histogram name="Renderer.PaintPreview.Capture.SubframeBlinkCaptureDuration"
    units="ms" expires_after="2023-05-27">
  <owner>ckitagawa@chromium.org</owner>
  <owner>fredmello@chromium.org</owner>
  <owner>chrome-fdt@google.com</owner>
  <summary>
    Records the number of milliseconds spent blocking Blink's main thread while
    capturing a subframe.
  </summary>
</histogram>

<histogram name="Renderer.PaintPreview.Capture.SubframeSuccess"
    enum="BooleanSuccess" expires_after="2023-05-27">
  <owner>ckitagawa@chromium.org</owner>
  <owner>fredmello@chromium.org</owner>
  <owner>chrome-fdt@google.com</owner>
  <summary>
    Records a boolean indicating whether a capture for a subframe succeeded.
  </summary>
</histogram>

<histogram name="Renderer.Preload.UnusedResource" enum="BooleanSuccess"
    expires_after="2024-02-17">
  <owner>yoavweiss@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram name="Renderer.ProcessLifetime3{RendererHostedContentType}"
    units="ms" expires_after="2023-02-28">
  <owner>fdoray@chromium.org</owner>
  <owner>olivierli@chromium.org</owner>
  <owner>catan-team@chromium.org</owner>
  <summary>
    The time elapsed between the creation and destruction of a renderer.
    Recorded for {RendererHostedContentType}.
  </summary>
  <token key="RendererHostedContentType" variants="RendererHostedContentType"/>
</histogram>

<histogram name="Renderer.RenderThreadImpl.Init" units="ms"
    expires_after="2023-10-22">
  <owner>jam@chromium.org</owner>
  <owner>sky@chromium.org</owner>
  <summary>
    The time it takes RenderThreadImpl::Init() to run, recorded for each
    renderer process.
  </summary>
</histogram>

<histogram name="RendererScheduler.IPC.FrameVisibility" enum="Boolean"
    expires_after="M85">
  <owner>altimin@chromium.org</owner>
  <owner>lpy@chromium.org</owner>
  <summary>
    This boolean keeps track the count of the visibility change of a frame.
    Recorded every time when the visibility of a frame is changed.
  </summary>
</histogram>

<histogram name="RendererScheduler.QueueingDuration.{Priority}Priority"
    units="microseconds" expires_after="2023-10-31">
  <owner>szager@chromium.org</owner>
  <owner>paint-dev@chromium.org</owner>
  <summary>
    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.
  </summary>
  <token key="Priority">
    <variant name="BestEffort"/>
    <variant name="Control"/>
    <variant name="High"/>
    <variant name="HighContinuation"/>
    <variant name="Highest"/>
    <variant name="Low"/>
    <variant name="LowContinaution"/>
    <variant name="Normal"/>
    <variant name="NormalContinuation"/>
    <variant name="VeryHigh"/>
  </token>
</histogram>

<histogram name="RendererScheduler.RendererMainThreadLoad5" units="%"
    expires_after="2023-09-03">
  <owner>altimin@chromium.org</owner>
  <summary>
    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.
  </summary>
</histogram>

<histogram base="true" name="RendererScheduler.TaskDurationPerFrameOriginType2"
    enum="RendererSchedulerFrameOriginType" expires_after="M85">
  <owner>altimin@chromium.org</owner>
  <summary>
    Total cpu time (reported in full seconds) of renderer tasks split by per
    frame origin type (main frame vs same-origin frame vs cross-origin frame).
    Note that partial seconds are rounded up/down so that they average to the
    correct value when many reports are added. For more details, check
    base::ScaledLinearHistogram.

    Note that this metric discards tasks longer than 30 seconds because they are
    considered to be a result of measurement glitch.
  </summary>
</histogram>

<histogram name="RendererScheduler.TaskTime2" units="microseconds"
    expires_after="never">
  <owner>sunyunjia@chromium.org</owner>
  <owner>altimin@chromium.org</owner>
  <summary>
    The duration of every task queued in the _renderer_ scheduler to see the
    distribution of the task duration.

    Note that this metric discards tasks longer than 30 seconds because they are
    considered to be a result of measurement glitch.

    Warning: This metric may include reports from clients with low-resolution
    clocks (i.e. on Windows, ref. |TimeTicks::IsHighResolution()|). Such reports
    will cause this metric to have an abnormal distribution. When considering
    revising this histogram, see UMA_HISTOGRAM_CUSTOM_MICROSECONDS_TIMES for the
    solution.
  </summary>
</histogram>

<histogram name="RendererScheduler.UpdateForSameDocumentNavigationCount"
    enum="SinglePageAppNavigationType" expires_after="M85">
  <owner>npm@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    The count of same-document-navigations split by whether it is the
    same-document backward/forward navigation, history API navigation, or other
    fragment navigation.
  </summary>
</histogram>

<histogram name="RendererSyncIPC.ElapsedTime" units="ms" expires_after="M85">
  <owner>ppi@chromium.org</owner>
  <summary>
    Roundtrip times for synchronous IPC calls from the renderer to browser.
  </summary>
</histogram>

</histograms>

</histogram-configuration>