tools/metrics/histograms/histograms_xml/event/histograms.xml

<!--
Copyright 2020 The Chromium Authors. All rights reserved.
Use of this source code is governed by a BSD-style license that can be
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<!--
This file is used to generate a comprehensive list of Event 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 send CLs to chromium-metrics-reviews@google.com rather than to specific
individuals. These CLs will be automatically reassigned to a reviewer within
about 5 minutes. This approach helps the metrics team to load-balance incoming
reviews. Googlers can read more about this at go/gwsq-gerrit.
-->

<histogram-configuration>

<histograms>

<histogram name="Event.AggregatedLatency.Renderer2" units="microseconds"
    expires_after="2021-06-06">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between initiation of any input event and the renderer receiving and
    starting to process it.

    Team: input-dev@chromium.org.

    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="Event.AndroidActionDown.ToolType" enum="MotionEventToolType"
    expires_after="never">
<!-- expires-never: Needed for long-term usage tracking for different types of
     pointers. -->

  <owner>mustaq@chromium.org</owner>
  <owner>nzolghadr@chromium.org</owner>
  <summary>
    Tracks the number of Android MotionEvents with ACTION_DOWN or
    ACTION_POINTER_DOWN or ACTION_BUTTON_PRESS for each ToolType (unknown,
    finger, mouse or stylus).

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.AsyncTargeting.AsyncClientDepth" units="clients"
    expires_after="2021-06-06">
  <owner>sadrul@chromium.org</owner>
  <owner>event-targeting@chromium.org</owner>
  <summary>
    Tracks how many clients were queried (asynchronously) to determine the
    target for an input event.
  </summary>
</histogram>

<histogram name="Event.AsyncTargeting.ResponseTime" units="ms"
    expires_after="2021-06-06">
  <owner>sadrul@chromium.org</owner>
  <owner>event-targeting@chromium.org</owner>
  <summary>
    Tracks how long it takes for a client to respond to an asynchronous request
    to find a target for an input event.
  </summary>
</histogram>

<histogram name="Event.BrowserVerifiedUserActivation" enum="BooleanSuccess"
    expires_after="2021-06-13">
  <owner>liviutinta@chromium.org</owner>
  <owner>mustaq@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Records whether Browser User Activation Verification is successful or not.
    We are interested in how many times the Browser User Activation Verification
    fails vs how many times it succeeds.
  </summary>
</histogram>

<histogram name="Event.ClickNotFiredDueToDomManipulation" enum="BooleanHit"
    expires_after="M82">
  <owner>nzolghadr@chromium.org</owner>
  <summary>
    Whether click target was affected by DOM manipulation or not.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.ClickTargetChangedDueToInteractiveElement"
    enum="BooleanHit" expires_after="M80">
  <owner>nzolghadr@chromium.org</owner>
  <summary>
    Whether click target was affected by interactive element being in the
    ancestor path.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram
    name="Event.DownEventCount.PerInputFormFactorDestinationCombination2"
    enum="DownEventInputFormFactorDestinationCombination2" expires_after="M100">
  <owner>tbuckley@chromium.org</owner>
  <summary>
    The number of down events received per destination, input and form factor
    combination.

    Input is down events generated by mouse/touch/stylus. Form factor is down
    events generated by clamshell/touchviewLandscape/touchviewPortrait.
    Destination: Every down event that is targeted to each destination will be
    counted including those that don't have an effect. For example: Tapping on a
    disabled button inside the browser frame will be treated as down events on
    browser window.
  </summary>
</histogram>

<histogram name="Event.FractionOfTimeWithoutUserInput" units="%"
    expires_after="2021-06-16">
  <owner>sullivan@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    For each 10 second window, reports the fraction of the time there was no
    user input. We consider there to be no user input if we haven't received any
    events for &gt; 50ms.
  </summary>
</histogram>

<histogram name="Event.FrameEventRouting.NoGestureTarget" units="units"
    expires_after="2020-02-23">
  <obsolete>
    Removed 2020.10.20 - no longer in use.
  </obsolete>
  <owner>wjmaclean@chromium.org</owner>
  <summary>
    Record whether we unexpectedly encounter an empty gesture queue while
    routing gesture events to frames' renderers: true =&gt; empty queue, false
    =&gt; non-empty queue.
  </summary>
</histogram>

<histogram name="Event.FrameEventRouting.TouchEventAckQueueSize" units="units"
    expires_after="2020-07-19">
  <obsolete>
    2020.10.21 - Removed.
  </obsolete>
  <owner>wjmaclean@chromium.org</owner>
  <owner>kenrb@chromium.org</owner>
  <summary>
    The size of the TouchEventAckQueue, recorded each time we process an event
    ack (the queue usually, but not always, decreases in size during ack
    processing). Ideally this queue will operate at length close to zero,
    depending on how long it takes for events to travel to a renderer and be
    processed and an ack sent back. As the size increases it indicates decreased
    responsiveness of renderers with respect to touch events. One purpose of
    this metric is to develop a sense of normal queue sizes for different
    platforms. Initially we expect queue length to be less than 20 most of the
    time, but this is a guess.
  </summary>
</histogram>

<histogram name="Event.GestureCreated" enum="UIEventType"
    expires_after="2020-03-01">
  <owner>kuscher@google.com</owner>
  <summary>
    The gesture-events recognized and dispatched by the browser gesture
    recognizer. This replaces Ash.GestureCreated, which did not record events on
    Android and Windows.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.HitTest" enum="EventHitTest" expires_after="2020-05-31">
  <obsolete>
    Removed in M88.
  </obsolete>
  <owner>dtapuska@chromium.org</owner>
  <summary>
    For each hit test, records whether it was a hit or miss, and why.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.HitTestValidity" enum="EventHitTestValidity"
    expires_after="M85">
  <owner>dtapuska@chromium.org</owner>
  <summary>
    For hit tests that are validated, records whether it was correct or not, and
    why.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.HitTestValidityScore" enum="EventHitTestValidityScore"
    expires_after="M85">
  <owner>dtapuska@chromium.org</owner>
  <summary>
    For hit tests that are invalid, records the score (a series of bits
    indicating what was matched and what wasn't).

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.InputEventPrediction.Scroll.OverPrediction"
    units="pixels" expires_after="M85">
  <owner>eirage@chromium.org</owner>
  <owner>axantoine@google.com</owner>
  <summary>
    Overshoot distance in pixels between a predicted scroll position and the
    corresponding interpolated real scroll position that occurred at the
    prediction time.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.InputEventPrediction.Scroll.PredictionJitter"
    units="pixels" expires_after="M85">
  <owner>eirage@chromium.org</owner>
  <owner>axantoine@google.com</owner>
  <summary>
    Euclidean distance in pixels between two successive variations of touch
    scroll deltas which are the difference between a predicted scroll position
    and its corresponding interpolated real position that occurred at prediction
    time.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.InputEventPrediction.Scroll.UnderPrediction"
    units="pixels" expires_after="M85">
  <owner>eirage@chromium.org</owner>
  <owner>axantoine@google.com</owner>
  <summary>
    Undershoot distance in pixels between a predicted scroll position and the
    corresponding interpolated real scroll position that occurred at the
    prediction time.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.InputEventPrediction.Scroll.VisualJitter" units="pixels"
    expires_after="M85">
  <owner>eirage@chromium.org</owner>
  <owner>axantoine@google.com</owner>
  <summary>
    Euclidean distance in pixels between two successive variations of touch
    scroll deltas which are the difference between a predicted scroll position
    and the interpolated real position that occurred at frame time.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.InputEventPrediction.Scroll.WrongDirection"
    enum="Boolean" expires_after="M85">
  <owner>eirage@chromium.org</owner>
  <owner>axantoine@google.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).

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.EndToEnd.KeyPress" units="microseconds"
    expires_after="2021-05-09">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the OS receiving a keyboard event and the resulting GPU frame
    swap. If no swap was induced by the event, no recording is made. Only
    recorded for key presses.

    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="Event.Latency.EndToEnd.Mouse" units="microseconds"
    expires_after="2020-11-08">
  <owner>nzolghadr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the OS receiving a mouse event and the resulting GPU frame
    swap. If no swap was induced by the event, no recording is made.

    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="Event.Latency.EndToEnd.TouchpadPinch" units="microseconds"
    expires_after="2020-10-11">
  <owner>nzolghadr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the OS receiving a touchpad pinch event and the resulting GPU
    frame swap. If no swap was induced by the event, no recording is made.
  </summary>
</histogram>

<histogram name="Event.Latency.EndToEnd.TouchpadPinch2" units="microseconds"
    expires_after="2021-06-20">
  <owner>nzolghadr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the OS receiving a touchpad pinch event and the resulting GPU
    frame swap. If no swap was induced by the event, no recording is made.
  </summary>
</histogram>

<histogram name="Event.Latency.EventToRender.TouchpadPinch"
    units="microseconds" expires_after="M81">
  <owner>nzolghadr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the OS receiving a touchpad pinch event and RenderWidgetHost
    sending event to render.
  </summary>
</histogram>

<histogram name="Event.Latency.HitTest" units="microseconds"
    expires_after="2021-07-11">
  <owner>schenney@chromium.org</owner>
  <owner>paint-dev@chromium.org</owner>
  <summary>
    Duration of a non-resurive hitTest operation. The hit test is non-recursive
    when the AllowChildFrameContent flag is clear. See also
    Event.Latency.HitTestRecusrive.

    Team: paint-dev@chromium.org.

    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="Event.Latency.HitTestRecursive" units="microseconds"
    expires_after="2021-07-11">
  <owner>schenney@chromium.org</owner>
  <owner>paint-dev@chromium.org</owner>
  <summary>
    Duration of a recursive hitTest operation. The hit test is recursive when
    the AllowChildFrameContent flag is set. See also Event.Latency.HitTest.

    Team: paint-dev@chromium.org.

    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="Event.Latency.OS" units="microseconds"
    expires_after="2020-11-01">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between input event received by OS and sent to Chrome.

    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="Event.Latency.OS_NO_VALIDATION.POSITIVE" units="ms"
    expires_after="2021-05-09">
  <owner>sullivan@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    For Mac, a version of Event.Latency.OS that has the positive values it would
    contain if ValidateEventTimeClock() were not called on the timestamps.

    This metric is intended to debug http://crbug.com/1039833, where very high
    numbers are seen for PageLoad.InputDelay3. The units of this metric are the
    same as PageLoad.InputDelay3 for consistency while debugging.
  </summary>
</histogram>

<histogram name="Event.Latency.Scroll.Wheel.TimeToHandled2"
    units="microseconds" expires_after="2021-06-16">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between initial creation of a wheel event and the generated
    ScrollUpdate gesture event is handled on main/impl thread (specified by
    suffix). If no swap was induced by the ScrollUpdate gesture event, no
    recording is made. Unlike Event.Latency.ScrollUpdate.Wheel.TimeToHandled2
    this metric includes the first GSU of every scrolling sequence as well.

    Team: input-dev@chromium.org.

    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="Event.Latency.Scroll.Wheel.TimeToScrollUpdateSwapBegin2"
    units="microseconds" expires_after="2020-06-21">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between initial creation of a wheel event and start of the frame swap
    on the GPU service caused by the generated ScrollUpdate gesture event. If no
    swap was induced by the event, no recording is made. Unlike
    Event.Latency.ScrollUpdate.Wheel.TimeToScrollUpdateSwapBegin2 this metric
    includes the first GSU of every scrolling sequence as well.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollBegin.Scrollbar.BrowserNotifiedToBeforeGpuSwap2"
    units="microseconds" expires_after="2021-06-13">
  <owner>nzolghadr@chromium.org</owner>
  <owner>dlibby@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the display compositor receives the notification of the first
    ScrollUpdate gesture event in a given scroll gesture event sequence with
    scrollbar source induced renderer swap and GPU starts to swap. The name
    contains BrowserNotified for consistency with the existing
    ScrollBegin/ScrollUpdate metrics - historically the display compositor lived
    in the browser process.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollBegin.Scrollbar.GpuSwap2"
    units="microseconds" expires_after="2021-06-27">
  <owner>nzolghadr@chromium.org</owner>
  <owner>dlibby@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between gpu starts to swap the first ScrollUpdate gesture event in a
    given scroll gesture event sequence with scrollbar source induced frame and
    the swap finishes.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollBegin.Scrollbar.HandledToRendererSwap2"
    units="microseconds" expires_after="2020-12-01">
  <owner>nzolghadr@chromium.org</owner>
  <owner>dlibby@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the first ScrollUpdate gesture event in a given scroll gesture
    event sequence with scrollbar source, is handled on main/impl thread
    (specified by suffix) and before renderer starts to swap.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollBegin.Scrollbar.RendererSwapToBrowserNotified2"
    units="microseconds" expires_after="2020-12-01">
  <owner>nzolghadr@chromium.org</owner>
  <owner>dlibby@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the renderer starts to swap a frame (generates compositor
    frame) induced by the first ScrollUpdate gesture event in a given scroll
    gesture event sequence with scrollbar source, and display compositor
    receives the submitted compositor frame. The name contains BrowserNotified
    for consistency with the existing ScrollBegin/ScrollUpdate metrics -
    historically the display compositor lived in the browser process.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollBegin.Scrollbar.TimeToHandled2"
    units="microseconds" expires_after="2020-12-01">
  <owner>nzolghadr@chromium.org</owner>
  <owner>dlibby@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between initial creation of a scrollbar event and the first generated
    ScrollUpdate gesture event in a given scroll gesture event sequence is
    handled on main/impl thread (specified by suffix). If no swap was induced by
    the ScrollUpdate gesture event, no recording is made.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollBegin.Scrollbar.TimeToScrollUpdateSwapBegin4"
    units="microseconds" expires_after="2021-06-06">
  <owner>nzolghadr@chromium.org</owner>
  <owner>dlibby@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    Time between initial creation of an input event that resulted in a scrollbar
    scroll and the start of the frame swap on the GPU service caused by the
    generated ScrollUpdate gesture event if that ScrollUpdate is the first such
    event in a given scroll gesture event sequence. If no swap was induced by
    the event, no recording is made.

    Do not modify this metric in any way without contacting
    speed-metrics-dev@chromium.org.

    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="Event.Latency.ScrollBegin.TimeToScrollUpdateSwapBegin2"
    units="microseconds" expires_after="2021-05-09">
  <owner>nzolghadr@chromium.org</owner>
  <summary>
    Time between initial creation of a wheel/touch event and start of the frame
    swap on the GPU service caused by the generated ScrollUpdate gesture event
    if that ScrollUpdate is the first such event in a given scroll gesture event
    sequence. If no swap was induced by the event, no recording is made. If no
    swap was induced by the event, no recording is made.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollBegin.TopControlsMoved" enum="Boolean"
    expires_after="2020-12-06">
  <owner>sadrul@chromium.org</owner>
  <owner>chrome-gpu-metrics@google.com</owner>
  <summary>
    Records whether the browser top-controls (i.e. omnibox, toolbar) moved
    because of the scroll-begin event (i.e. the first scroll-update event of
    that sequence).
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollBegin.Touch.AverageLag" units="pixels"
    expires_after="2021-06-20">
  <owner>flackr@chromium.org</owner>
  <owner>joalmei@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Measures an average distance that represents how the page sticks to the
    finger when user scrolls. Only reports touch scrolling. See
    https://docs.google.com/document/d/154jddNiKtxELBvrjLz9v6A7sA1J3iwQQzySHgtY12Oo/

    This is the lag caused by the Gesture Scroll Begin Event. In each touch
    interaction there is a GSB followed by multiple Gesture Scroll Updates,
    which are separately logged by Event.Latency.ScrollUpdate.Touch.AverageLag.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollBegin.Touch.AverageLagPresentation"
    units="pixels" expires_after="2021-06-20">
  <owner>flackr@chromium.org</owner>
  <owner>joalmei@microsoft.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Measures an average distance that represents how the page sticks to the
    finger when user scrolls. Only reports touch scrolling. See
    https://docs.google.com/document/d/154jddNiKtxELBvrjLz9v6A7sA1J3iwQQzySHgtY12Oo/

    This is the lag caused by the Gesture Scroll Begin Event. In each touch
    interaction there is a GSB followed by multiple Gesture Scroll Updates,
    which are separately logged by
    Event.Latency.ScrollUpdate.Touch.AverageLagPresentation.

    The difference between AverageLag and AverageLagPresentation is that the
    former uses the Gpu Swap Begin Time as an approximation for the time the
    frame is visible on the screen, while the latter uses the Presentation Time.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram
    name="Event.Latency.ScrollBegin.Touch.BrowserNotifiedToBeforeGpuSwap2"
    units="microseconds" expires_after="2020-12-06">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between the browser receives the notification of the first ScrollUpdate
    gesture event in a given scroll gesture event sequence with touch source
    induced renderer swap and GPU starts to swap.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollBegin.Touch.GpuSwap2" units="microseconds"
    expires_after="2021-06-06">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between gpu starts to swap the first ScrollUpdate gesture event in a
    given scroll gesture event sequence with touch source induced frame and the
    swap finishes.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollBegin.Touch.HandledToRendererSwap2"
    units="microseconds" expires_after="2021-06-16">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the first ScrollBegin gesture event in a given scroll gesture
    event sequence with touch source, is handled on main/impl thread (specified
    by suffix) and before renderer starts to swap.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollBegin.Touch.RendererSwapToBrowserNotified2"
    units="microseconds" expires_after="2021-06-16">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the renderer starts to swap a frame induced by the first
    ScrollUpdate gesture event in a given scroll gesture event sequence with
    touch source, and browser receives the swap notification.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollBegin.Touch.TimeToHandled2"
    units="microseconds" expires_after="2021-06-20">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between initial creation of a touch event and the first generated
    ScrollBegin gesture event in a given scroll gesture event sequence is
    handled on main/impl thread (specified by suffix). If no swap was induced by
    the ScrollUpdate gesture event, no recording is made.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollBegin.Touch.TimeToScrollUpdateSwapBegin4"
    units="microseconds" expires_after="2021-06-16">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    Time between initial creation of a touch event and the start of the frame
    swap on the GPU service caused by the generated ScrollUpdate gesture event
    if that ScrollUpdate is the first such event in a given scroll gesture event
    sequence. If no swap was induced by the event, no recording is made.

    Do not modify this metric in any way without contacting
    speed-metrics-dev@chromium.org.

    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="Event.Latency.ScrollBegin.Wheel.BrowserNotifiedToBeforeGpuSwap2"
    units="microseconds" expires_after="2020-11-29">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between the browser receives the notification of the first ScrollUpdate
    gesture event in a given scroll gesture event sequence with wheel source
    induced renderer swap and GPU starts to swap.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollBegin.Wheel.GpuSwap2" units="microseconds"
    expires_after="2021-06-16">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between gpu starts to swap the first ScrollUpdate gesture event in a
    given scroll gesture event sequence with wheel source induced frame and the
    swap finishes.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollBegin.Wheel.HandledToRendererSwap2"
    units="microseconds" expires_after="2021-07-16">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the first ScrollUpdate gesture event in a given scroll gesture
    event sequence with wheel source, is handled on main/impl thread (specified
    by suffix) and before renderer starts to swap.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollBegin.Wheel.RendererSwapToBrowserNotified2"
    units="microseconds" expires_after="2021-07-13">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the renderer starts to swap a frame induced by the first
    ScrollUpdate gesture event in a given scroll gesture event sequence with
    wheel source, and browser receives the swap notification.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollBegin.Wheel.TimeToHandled2"
    units="microseconds" expires_after="2021-06-26">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between initial creation of a wheel event and the first generated
    ScrollUpdate gesture event in a given scroll gesture event sequence is
    handled on main/impl thread (specified by suffix). If no swap was induced by
    the ScrollBegin gesture event, no recording is made.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollBegin.Wheel.TimeToScrollUpdateSwapBegin4"
    units="microseconds" expires_after="2021-06-27">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between initial creation of a wheel event and the start of the frame
    swap on the GPU service caused by the generated ScrollUpdate gesture event
    if that ScrollUpdate is the first such event in a given scroll gesture event
    sequence. If no swap was induced by the event, no recording is made.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollInertial.Touch.BrowserNotifiedToBeforeGpuSwap2"
    units="microseconds" expires_after="M80">
  <owner>nzolghad@chromium.org</owner>
  <summary>
    Time between the browser receives the notification of a ScrollUpdate gesture
    generated from a touchscreen fling induced renderer swap and GPU starts to
    swap.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollInertial.Touch.GpuSwap2"
    units="microseconds" expires_after="2021-06-16">
  <owner>nzolghadr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between gpu starts to swap a ScrollUpdate gesture event generated from
    a touchscreen fling induced frame and the swap finishes.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollInertial.Touch.HandledToRendererSwap2"
    units="microseconds" expires_after="M80">
  <owner>nzolghadr@chromium.org</owner>
  <summary>
    Time between a ScrollUpdate gesture event generated from a touchscreen
    fling, is handled on main/impl thread (specified by suffix) and before
    renderer starts to swap.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram
    name="Event.Latency.ScrollInertial.Touch.RendererSwapToBrowserNotified2"
    units="microseconds" expires_after="2021-06-16">
  <owner>nzolghadr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the renderer starts to swap a frame induced by a ScrollUpdate
    gesture event generated from a touchscreen fling, and browser receives the
    swap notification.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollInertial.Touch.TimeToHandled2"
    units="microseconds" expires_after="M80">
  <owner>nzolghadr@chromium.org</owner>
  <summary>
    Time between initial creation of a ScrollUpdate gesture event generated from
    a touchscreen fling is handled on main/impl thread (specified by suffix). If
    no swap was induced by the ScrollUpdate gesture event, no recording is made.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram
    name="Event.Latency.ScrollInertial.Touch.TimeToScrollUpdateSwapBegin4"
    units="microseconds" expires_after="2021-01-24">
  <owner>nozlghadr@chromium.org</owner>
  <summary>
    Time between initial creation of a ScrollUpdate gesture event generated from
    a touchscreen fling and the start of the frame swap on the GPU service
    caused by the generated ScrollUpdate gesture event. If no swap was induced
    by the event, no recording is made.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram
    name="Event.Latency.ScrollUpdate.Scrollbar.BrowserNotifiedToBeforeGpuSwap2"
    units="microseconds" expires_after="2021-12-01">
  <owner>flackr@chromium.org</owner>
  <owner>arakeri@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the display compositor receives the notification of the first
    ScrollUpdate gesture event in a given scroll gesture event sequence with
    scrollbar source induced renderer swap and GPU starts to swap. The name
    contains BrowserNotified for consistency with the existing
    ScrollBegin/ScrollUpdate metrics - historically the display compositor lived
    in the browser process.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollUpdate.Scrollbar.GpuSwap2"
    units="microseconds" expires_after="2021-12-01">
  <owner>flackr@chromium.org</owner>
  <owner>arakeri@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between gpu starts to swap a ScrollUpdate gesture event with scrollbar
    source induced frame and the swap finishes.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollUpdate.Scrollbar.HandledToRendererSwap2"
    units="microseconds" expires_after="2021-12-01">
  <owner>flackr@chromium.org</owner>
  <owner>arakeri@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the ScrollUpdate gesture event with scrollbar source, is
    handled on main/impl thread (specified by suffix) and before renderer starts
    to swap.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollUpdate.Scrollbar.RendererSwapToBrowserNotified2"
    units="microseconds" expires_after="2021-12-01">
  <owner>flackr@chromium.org</owner>
  <owner>arakeri@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the renderer starts to swap a frame (generates compositor
    frame) induced by the first ScrollUpdate gesture event in a given scroll
    gesture event sequence with scrollbar source, and display compositor
    receives the submitted compositor frame. The name contains BrowserNotified
    for consistency with the existing ScrollBegin/ScrollUpdate metrics -
    historically the display compositor lived in the browser process.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollUpdate.Scrollbar.TimeToHandled2"
    units="microseconds" expires_after="2021-12-01">
  <owner>flackr@chromium.org</owner>
  <owner>arakeri@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between initial creation of an input event that results in a scrollbar
    scroll and the generated ScrollUpdate gesture event is handled on main/impl
    thread (specified by suffix). If no swap was induced by the ScrollUpdate
    gesture event, no recording is made.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollUpdate.Scrollbar.TimeToScrollUpdateSwapBegin4"
    units="microseconds" expires_after="2021-12-01">
  <owner>flackr@chromium.org</owner>
  <owner>arakeri@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    Time between initial creation of a scrollbar event and start of the frame
    swap on the GPU service caused by the generated ScrollUpdate gesture event.
    If no swap was induced by the event, no recording is made. The first GSU of
    every scrolling sequence is excluded from this metric.

    Do not modify this metric in any way without contacting
    speed-metrics-dev@chromium.org.

    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="Event.Latency.ScrollUpdate.TimeToScrollUpdateSwapBegin2"
    units="microseconds" expires_after="2021-06-06">
  <owner>nzolghadr@chromium.org</owner>
  <summary>
    Time between initial creation of a wheel/touch event and start of the frame
    swap on the GPU service caused by the generated ScrollUpdate gesture event.
    If no swap was induced by the event, no recording is made. The first GSU of
    every scrolling sequence is excluded from this metric.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollUpdate.TopControlsMoved" enum="Boolean"
    expires_after="2020-08-02">
  <owner>sadrul@chromium.org</owner>
  <owner>chrome-gpu-metrics@google.com</owner>
  <summary>
    Records whether the browser top-controls (i.e. omnibox, toolbar) moved
    because of the scroll-update event (other than the first update event in the
    sequence).
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollUpdate.Touch.AverageLag" units="pixels"
    expires_after="2021-06-20">
  <owner>flackr@chromium.org</owner>
  <owner>joalmei@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Measures an average distance that represents how the page sticks to the
    finger when user scrolls. Only reports touch scrolling. See
    https://docs.google.com/document/d/154jddNiKtxELBvrjLz9v6A7sA1J3iwQQzySHgtY12Oo/

    This is the lag caused by the Gesture Scroll Updates occourring in the
    lifetime of a scroll interaction.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram
    name="Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionNegative"
    units="pixels" expires_after="M90">
  <owner>flackr@chromium.org</owner>
  <owner>joalmei@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Measures the negative impact on the AverageLag metric that is attributable
    to scroll prediction. This value has the same units as
    Event.Latency.ScrollUpdate.Touch.AverageLag but is a difference between that
    value and what it would have been if prediction was disabled.

    PredictionNegative is logged when prediction caused an increase in perceived
    lag (i.e. the rendered position was on average further from the actual
    location of the finger) for a given interaction/interval. The duration of
    the interaction/interval is either 1s, or the time from when the user starts
    scrolling to lifting the finger, whichever is smaller.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram
    name="Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionPositive"
    units="pixels" expires_after="M90">
  <owner>flackr@chromium.org</owner>
  <owner>joalmei@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Measures the positive impact on the AverageLag metric that is attributable
    to scroll prediction. This value has the same units as
    Event.Latency.ScrollUpdate.Touch.AverageLag but is a difference between that
    value and what it would have been if prediction was disabled.

    PredictionPostive is logged when prediction caused a decrease in perceived
    lag (i.e. the rendered position was on average closer to the actual location
    of the finger) for a given interaction/interval. The duration of the
    interaction/interval is either 1s, or the time from when the user starts
    scrolling to lifting the finger, whichever is smaller.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollUpdate.Touch.AverageLagPresentation"
    units="pixels" expires_after="2021-06-20">
  <owner>flackr@chromium.org</owner>
  <owner>joalmei@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Measures an average distance that represents how the page sticks to the
    finger when user scrolls. Only reports touch scrolling. See
    https://docs.google.com/document/d/154jddNiKtxELBvrjLz9v6A7sA1J3iwQQzySHgtY12Oo/

    This is the lag caused by the Gesture Scroll Updates occurring in the
    lifetime of a scroll interaction.

    The difference between AverageLag and AverageLagPresentation is that the
    former uses the Gpu Swap Begin Time as an approximation for the time the
    frame is visible on the screen, while the latter uses the Presentation Time.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram
    name="Event.Latency.ScrollUpdate.Touch.AverageLagPresentation.PredictionNegative"
    units="pixels" expires_after="M90">
  <owner>flackr@chromium.org</owner>
  <owner>joalmei@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Measures the negative impact on the AverageLagPresentation metric that is
    attributable to scroll prediction. This value has the same units as
    Event.Latency.ScrollUpdate.Touch.AverageLagPresentation but is a difference
    between that value and what it would have been if prediction was disabled.

    PredictionNegative is logged when prediction caused an increase in perceived
    lag (i.e. the rendered position was on average further from the actual
    location of the finger) for a given interaction/interval. The duration of
    the interaction/interval is either 1s, or the time from when the user starts
    scrolling to lifting the finger, whichever is smaller.

    The difference between AverageLag and AverageLagPresentation is that the
    former uses the Gpu Swap Begin Time as an approximation for the time the
    frame is visible on the screen, while the latter uses the Presentation Time.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram
    name="Event.Latency.ScrollUpdate.Touch.AverageLagPresentation.PredictionPositive"
    units="pixels" expires_after="M90">
  <owner>flackr@chromium.org</owner>
  <owner>joalmei@microsoft.com</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Measures the positive impact on the AverageLagPresentation metric that is
    attributable to scroll prediction. This value has the same units as
    Event.Latency.ScrollUpdate.Touch.AverageLagPresentation but is a difference
    between that value and what it would have been if prediction was disabled.

    PredictionPostive is logged when prediction caused a decrease in perceived
    lag (i.e. the rendered position was on average closer to the actual location
    of the finger) for a given interaction/interval. The duration of the
    interaction/interval is either 1s, or the time from when the user starts
    scrolling to lifting the finger, whichever is smaller.

    The difference between AverageLag and AverageLagPresentation is that the
    former uses the Gpu Swap Begin Time as an approximation for the time the
    frame is visible on the screen, while the latter uses the Presentation Time.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram
    name="Event.Latency.ScrollUpdate.Touch.BrowserNotifiedToBeforeGpuSwap2"
    units="microseconds" expires_after="M85">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between the browser receives the notification of a ScrollUpdate gesture
    event with touch source induced renderer swap and GPU starts to swap.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollUpdate.Touch.GpuSwap2"
    units="microseconds" expires_after="2021-06-06">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between gpu starts to swap a ScrollUpdate gesture event with touch
    source induced frame and the swap finishes.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollUpdate.Touch.HandledToRendererSwap2"
    units="microseconds" expires_after="2020-12-06">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between the ScrollUpdate gesture event with touch source, is handled on
    main/impl thread (specified by suffix) and before renderer starts to swap.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollUpdate.Touch.RendererSwapToBrowserNotified2"
    units="microseconds" expires_after="2021-06-20">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the renderer starts to swap a frame induced by ScrollUpdate
    gesture event with touch source, and browser receives the swap notification.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollUpdate.Touch.TimeToHandled2"
    units="microseconds" expires_after="2021-06-13">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between initial creation of a touch event and the generated
    ScrollUpdate gesture event is handled on main/impl thread (specified by
    suffix). If no swap was induced by the ScrollUpdate gesture event, no
    recording is made.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollUpdate.Touch.TimeToScrollUpdateSwapBegin4"
    units="microseconds" expires_after="never">
<!-- expires-never: guiding metric (internal: go/chrome-browser-guiding-metrics) -->

  <owner>flackr@chromium.org</owner>
  <owner>sullivan@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <owner>chrome-analysis-team@google.com</owner>
  <summary>
    Time between initial creation of a touch event and start of the frame swap
    on the GPU service caused by the generated ScrollUpdate gesture event. If no
    swap was induced by the event, no recording is made. The first GSU of every
    scrolling sequence is excluded from this metric.

    Do not modify this metric in any way without contacting
    speed-metrics-dev@chromium.org AND chrome-analysis-team@google.com.

    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="Event.Latency.ScrollUpdate.Wheel.BrowserNotifiedToBeforeGpuSwap2"
    units="microseconds" expires_after="2020-12-06">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between the browser receives the notification of a ScrollUpdate gesture
    event with wheel source induced renderer swap and GPU starts to swap.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollUpdate.Wheel.GpuSwap2"
    units="microseconds" expires_after="2021-06-16">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between gpu starts to swap a ScrollUpdate gesture event with wheel
    source induced frame and the swap finishes.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollUpdate.Wheel.HandledToRendererSwap2"
    units="microseconds" expires_after="2020-12-27">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between the ScrollUpdate gesture event with wheel source, is handled on
    main/impl thread (specified by suffix) and before renderer starts to swap.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollUpdate.Wheel.RendererSwapToBrowserNotified2"
    units="microseconds" expires_after="2021-07-13">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Time between the renderer starts to swap a frame induced by ScrollUpdate
    gesture event with wheel source, and browser receives the swap notification.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Latency.ScrollUpdate.Wheel.TimeToHandled2"
    units="microseconds" expires_after="2021-01-17">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between initial creation of a wheel event and the generated
    ScrollUpdate gesture event is handled on main/impl thread (specified by
    suffix). If no swap was induced by the ScrollUpdate gesture event, no
    recording is made. The first GSU of every scrolling sequence is excluded
    from this metric.

    Team: input-dev@chromium.org.

    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="Event.Latency.ScrollUpdate.Wheel.TimeToScrollUpdateSwapBegin4"
    units="microseconds" expires_after="2021-06-27">
  <owner>flackr@chromium.org</owner>
  <summary>
    Time between initial creation of a wheel event and start of the frame swap
    on the GPU service caused by the generated ScrollUpdate gesture event. If no
    swap was induced by the event, no recording is made. The first GSU of every
    scrolling sequence is excluded from this metric.

    Team: input-dev@chromium.org.

    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="Event.LatencyInfo.Debug.SourceIdConsistency"
    enum="SourceIdConsistency" expires_after="2020-09-01">
  <owner>tommckee@chromium.org</owner>
  <owner>speed-metrics-dev@chromium.org</owner>
  <summary>
    When tracking input event latency, we expect to associate some number of
    latency records (instances of ui::LatencyInfo) with a CompositorFrame. Each
    record is associated to a particular navigation through its ukm::SourceId
    property. This histogram tracks how often the records of an individual frame
    have varying or invalid source ids. See crbug.com/1062764.
  </summary>
</histogram>

<histogram name="Event.PassiveListeners" enum="EventResultType"
    expires_after="2021-06-06">
  <owner>dtapuska@chromium.org</owner>
  <summary>
    The result of handling of MouseWheel, TouchStart, TouchMove, TouchEnd events
    in the renderer.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.SingleTapType" enum="TapDelayType" expires_after="M85">
  <owner>flackr@chromium.org</owner>
  <summary>
    On non-mobile sites, gesture taps are delayed to prevent double taps from
    sending a click event. This stat counts the number of taps that are delayed
    by the double-tap delay versus those that are sent immediately on mobile
    sites.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Touch.FilteredAtPassthroughQueue"
    enum="EventPreFilterResult" expires_after="2020-03-22">
  <owner>charliea@chromium.org</owner>
  <owner>nzolghadr@chromium.org</owner>
  <summary>
    Whether a given touch event is filtered by the passthrough touch event queue
    or not. If the event was filtered, a reason is given. Potential reasons for
    filtering include the page not having any registered touch handlers and the
    renderer process not responding to previous touch events.

    Team: input-dev@chromium.org
  </summary>
</histogram>

<histogram name="Event.Touch.GestureTarget" enum="BrowserGestureActionType"
    expires_after="2020-06-28">
  <owner>kuscher@google.com</owner>
  <owner>rbyers@chromium.org</owner>
  <summary>
    The gesture-events recognized and dispatched for UI components owned by the
    browser. This histogram was created as part of separating gesture events
    between the browser and Ash (crbug.com/826476). The enums are extracted from
    Ash.GestureTarget.
  </summary>
</histogram>

<histogram name="Event.Touch.TimedOutOnDesktopSite" enum="BooleanTimedOut"
    expires_after="2021-06-15">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    On non-mobile-optimized (desktop) sites, whether the ack response from the
    renderer for any event in a contiguous touch sequence exceeds the
    desktop-specific timeout threshold.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.Touch.TimedOutOnMobileSite" enum="BooleanTimedOut"
    expires_after="2021-06-15">
  <owner>flackr@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    On mobile-optimized sites, whether the ack response from the renderer for
    any event in a contiguous touch sequence exceeds the mobile-specific timeout
    threshold.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.TouchDuration" units="ms" expires_after="M77">
  <owner>kuscher@google.com</owner>
  <owner>flackr@chromium.org</owner>
  <summary>
    The duration of a touch-sequence. Only measured for single finger gestures.
    This replaces Ash.TouchDuration2, which did not record events on Android and
    Windows.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.TouchMaxDistance" units="pixels" expires_after="M77">
  <owner>kuscher@google.com</owner>
  <owner>flackr@chromium.org</owner>
  <summary>
    The maximum euclidean distance in dips (device independent pixel) which a
    touch point has travelled away from its starting point. Only measured for
    single finger gestures. This replaces Ash.TouchMaxDistance, which did not
    record events on Android and Windows.

    Team: input-dev@chromium.org.
  </summary>
</histogram>

<histogram name="Event.TouchSelection.Duration" units="ms" expires_after="M77">
  <owner>nzolghadr@chromium.org</owner>
  <summary>
    Duration of touch selection sequence which finished with the user selecting
    one of the text manipulation actions, such as copy, cut, or paste. The
    duration is measured from the moment the text selection handles are shown,
    and until the action is executed.
  </summary>
</histogram>

<histogram name="Event.TouchSelection.EndedWithAction" enum="BooleanSuccess"
    expires_after="M77">
  <owner>nzolghadr@chromium.org</owner>
  <summary>
    Whether the touch selection sequence ended with the user selecting one of
    the text manipulation actions, such as copy, cut, or paste. after startup).
    Sequences ending with such action are considered successful.
  </summary>
</histogram>

<histogram name="Event.TouchSelection.WasDraggedDuration" units="ms"
    expires_after="M81">
  <owner>nzolghadr@chromium.org</owner>
  <summary>
    Duration of touch selection sequence which involved dragging a text
    selection handle. The duration is measured from the moment the text
    selection handles are shown, and until they are dismissed.
  </summary>
</histogram>

<histogram name="Event.TouchSelectionHandle.BestVerticalClippingPercentage"
    units="%" expires_after="M77">
  <owner>amaralp@chromium.org</owner>
  <summary>
    Percentage of touch handle height that would be clipped by the viewport in
    the best case of flipping or not flipping.
  </summary>
</histogram>

<histogram name="Event.TouchSelectionHandle.BottomHandleClippingPercentage"
    units="%" expires_after="M77">
  <owner>amaralp@chromium.org</owner>
  <summary>
    Percentage of touch handle height that would be clipped by the viewport if
    the handle was not vertically flipped.
  </summary>
</histogram>

<histogram name="Event.TouchSelectionHandle.FlippingImprovementPercentage"
    units="%" expires_after="M77">
  <owner>amaralp@chromium.org</owner>
  <summary>
    The difference between the metrics |BottomHandleClippingPercentage| and
    |BestVerticalClippingPercentage|. Measures how useful vertical flipping is.
  </summary>
</histogram>

<histogram name="Event.TouchSelectionHandle.LeftHandleClippingPercentage"
    units="%" expires_after="M77">
  <owner>amaralp@chromium.org</owner>
  <summary>
    Percentage of left touch handle width that would be clipped by the viewport
    without flipping.
  </summary>
</histogram>

<histogram name="Event.TouchSelectionHandle.RightHandleClippingPercentage"
    units="%" expires_after="M77">
  <owner>amaralp@chromium.org</owner>
  <summary>
    Percentage of right touch handle width that would be clipped by the viewport
    without flipping.
  </summary>
</histogram>

<histogram name="Event.TouchSelectionHandle.ShouldFlipHandleVertically"
    enum="TouchHandleVerticallyFlipped" expires_after="M77">
  <owner>amaralp@chromium.org</owner>
  <summary>
    Whether flipping the handle vertically would result in less clipping.
  </summary>
</histogram>

<histogram name="Event.UserActivation.TriggerFor{ActivationGatedApiType}"
    enum="UserActivationTriggerEnum" expires_after="2021-03-31">
  <owner>mustaq@chromium.org</owner>
  <owner>input-dev@chromium.org</owner>
  <summary>
    Tracks the notification-type for the user activation that resulted in a
    successful call for an activation-gated API (of type sticky, transient or
    consuming).
  </summary>
  <token key="ActivationGatedApiType">
    <variant name="Consuming"/>
    <variant name="Sticky"/>
    <variant name="Transient"/>
  </token>
</histogram>

<histogram name="Event.VizHitTest.AsyncHitTestReasons"
    enum="AsyncHitTestReasons" expires_after="2021-06-06">
  <owner>sadrul@chromium.org</owner>
  <owner>event-targeting@chromium.org</owner>
  <summary>
    Tracks the reasons why sychronous hit testing could not be done for each hit
    test requests processd by HitTestQuery.
  </summary>
</histogram>

<histogram name="Event.VizHitTest.HitTestDataIsEqualAccuracy"
    enum="BooleanAccuracy" expires_after="2021-01-03">
  <owner>zandershah@google.com</owner>
  <owner>event-targeting@chromium.org</owner>
  <summary>
    Tracks the result of AsyncLayerTreeFrameSink calls to
    HitTestRegionList::IsEqual.
  </summary>
</histogram>

<histogram name="Event.WaylandDragDrop.IncomingDataTransferTime" units="ms"
    expires_after="M90">
  <owner>rjkroege@chromium.org</owner>
  <owner>adunaev@igalia.com</owner>
  <summary>
    Delay between the drag coming into the window and the window is actually
    notified.
  </summary>
</histogram>

<histogram base="true" name="EventLatency" units="microseconds"
    expires_after="2021-05-09">
  <owner>mohsen@chromium.org</owner>
  <owner>graphics-dev@chromium.org</owner>
  <summary>
    Tracks the duration of various stages an event goes through from when it is
    generated on the browser side until it ends up generating a frame that is
    eventually presented to the user. If the frame is dropped, nothing is
    reported.

    This histogram only records metrics on machines with high-resolution clocks.
  </summary>
</histogram>

</histograms>

</histogram-configuration>