<!--
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 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 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
[email protected].
-->
<histogram-configuration>
<histograms>
<variants name="ScrollEventType">
<variant name="FirstGestureScrollUpdate"
summary="gesture-scroll-update events that are the first one in a
scroll sequence"/>
<variant name="GestureScrollBegin" summary="gesture-scroll-begin events"/>
<variant name="GestureScrollEnd" summary="gesture-scroll-end events"/>
<variant name="GestureScrollUpdate"
summary="gesture-scroll-update events that are non-inertial (i.e. not
generated due to a user fling) and not the first one in a
scroll sequence"/>
<variant name="InertialGestureScrollUpdate"
summary="gesture-scroll-update events that are inertial (i.e. generated
due to a user fling)"/>
</variants>
<variants name="ScrollJankOperator">
<variant name="Max" summary="maximum number of vsyncs a frames was delayed"/>
<variant name="Sum" summary="sum of missed vsyncs across all frames"/>
</variants>
<variants name="ScrollLength">
<variant name="" summary="all scrolls"/>
<variant name=".Large"
summary="large scrolls - number of presented frames more than 64"/>
<variant name=".Medium"
summary="medium length scrolls - number of presented frames between
[17,64]"/>
<variant name=".Small"
summary="small scrolls - number of presented frames between [1,16]"/>
</variants>
<histogram name="Event.AndroidActionDown.ToolType" enum="MotionEventToolType"
expires_after="never">
<!-- expires-never: Needed for long-term usage tracking for different types of
pointers. -->
<owner>[email protected]</owner>
<owner>[email protected]</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: [email protected].
</summary>
</histogram>
<histogram
name="Event.DownEventCount.PerInputFormFactorDestinationCombination2"
enum="DownEventInputFormFactorDestinationCombination2"
expires_after="2025-01-05">
<owner>[email protected]</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.EscKeyPressedDownWithModifier" enum="Boolean"
expires_after="2024-07-15">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Records whether the Esc key is pressed down with another modifier key.
Recorded when a Esc Key press event is prehandled by the browser, regardless
of whether keyboard/pointer/fullscreen is enabled.
</summary>
</histogram>
<histogram name="Event.GestureCreated" enum="UIEventType"
expires_after="2025-02-10">
<owner>[email protected]</owner>
<owner>[email protected]</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.
Note: this metric was expired from 2020-03-01 to 2023-04-04.
</summary>
</histogram>
<histogram name="Event.GestureScrollEnd.BrowserCompositorFrame.Count"
units="counts" expires_after="2025-05-02">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Records the number of compositor frames submitted by browser main between a
GestureScrollBegin and the corresponding GestureScrollEnd event. Recorded
when a GestureScrollEnd is received.
</summary>
</histogram>
<histogram name="Event.InputEventPrediction.Scroll.Frame{ScoreType}"
units="pixels" expires_after="2024-12-30">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
NOTE: this metric was expired from M97 to 2023-03-14. Overshoot distance in
pixels between a predicted scroll position and the corresponding
interpolated real scroll position that occurred at the frame time.
The difference between {ScoreType} and Frame{ScoreType} is the former uses
prediction time and the later uses frame time.
Team: [email protected].
</summary>
<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="Event.InputEventPrediction.Scroll.PredictionJitter"
units="pixels" expires_after="2025-03-13">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
NOTE: this metric was expired from M97 to 2023-03-14 and from 2024-03-13 to
2024-06-28. 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: [email protected].
</summary>
</histogram>
<histogram name="Event.InputEventPrediction.Scroll.VisualJitter" units="pixels"
expires_after="2025-03-13">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
NOTE: this metric was expired from M97 to 2023-03-14 and from 2024-03-13 to
2024-06-28. 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: [email protected].
</summary>
</histogram>
<histogram name="Event.InputEventPrediction.Scroll.{ScoreType}" units="pixels"
expires_after="2025-01-26">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
NOTE: this metric was expired from M97 to 2023-03-14. Overshoot distance in
pixels between a predicted scroll position and the corresponding
interpolated real scroll position that occurred at the frame time.
Team: [email protected].
</summary>
<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="Event.Jank.PredictorJankyFramePercentage2" units="%"
expires_after="2025-02-02">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
A frame is deemed janky if an irregular jump in screen displacement occured
in consecutive frames, this metric is the percentage of those janky frames
per 64 produced frames and is only emitted if a scroll has 64 frames in a
sequence. This metric is used to asses the scrolling prediction performance
as the scroll predictor should smooth out those irregular jumps.
For more details about this metric, please check
http://doc/1Y0u0Tq5eUZff75nYUzQVw6JxmbZAW9m64pJidmnGWsY.
Example of a slow scroll: https://youtube.com/shorts/K1ZhyjYr0No
Example of a fast scroll: https://youtube.com/shorts/dGj6XTD-PYA
</summary>
</histogram>
<histogram
name="Event.Jank.ScrollUpdate.{ScrollSpeed}.{VsyncStatus}.FrameAboveJankyThreshold2"
units="ratio * 100" expires_after="2025-02-10">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
This metric is the ratio between a larger screen displacement divided by a
following small screen displacement {ScrollSpeed}. If the larger screen
displacement was deemed janky given the predictor performance, and is only
emitted if there is {VsyncStatus}. This metric is used to asses the
scrolling prediction performance as the scroll predictor should smooth out
those irregular jumps.
For more details about this metric, please check
http://doc/1Y0u0Tq5eUZff75nYUzQVw6JxmbZAW9m64pJidmnGWsY.
</summary>
<token key="VsyncStatus">
<variant name="MissedVsync" summary="a missed vsync"/>
<variant name="NoMissedVsync" summary="no missed vsync"/>
</token>
<token key="ScrollSpeed">
<variant name="FastScroll"
summary="offset by 1.2, the jank threshold for fast scrolls.
|d_large/d_small - 1.2|"/>
<variant name="SlowScroll"
summary="offset by 1.4, the jank threshold for slow scrolls.
|d_large/d_small - 1.4|"/>
</token>
</histogram>
<histogram name="Event.Latency.OS2.{EventType}" units="ms"
expires_after="2025-02-16">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Time between input event received by OS and sent to Chrome, recorded for
each event when it is received by Chrome. Replaced Event.Latency.OS which
was calculated incorrectly on Windows.
Warning: On Windows, the timestamps of most events come from a clock with a
several msec resolution so will have an abnormal distribution even when
TimeTicks::IsHighResolution returns true. The exception is touch events
which usually come from the high-resolution clock when
TimeTicks::IsHighResolution returns true.
Note: As of May 29 2024 (M127), the calculation has been updated to be
optimistic about the low-frequency clock on Windows (0ms if <= 1x 16ms
tick), hence a -16ms shift is expected in the distribution.
</summary>
<token key="EventType">
<variant name="KEY_PRESSED"/>
<variant name="MOUSE_PRESSED"/>
<variant name="MOUSE_WHEEL"/>
<variant name="TOUCH_MOVED"/>
<variant name="TOUCH_PRESSED"/>
<variant name="TOUCH_RELEASED"/>
</token>
</histogram>
<histogram name="Event.Latency.ScrollBegin.Touch.AverageLagPresentation"
units="pixels" expires_after="2025-02-10">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</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 observed in processing 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.
Note: This histogram was expired from 2022-05-01 to 2023-06-20.
Team: [email protected].
</summary>
</histogram>
<histogram
name="Event.Latency.ScrollBegin.Touch.AverageLagPresentation.NoPrediction"
units="pixels" expires_after="2025-02-10">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Measures an average distance that represents how the page sticks to the
finger when user scrolls if prediction was disabled. Only reports touch
scrolling. See
https://docs.google.com/document/d/154jddNiKtxELBvrjLz9v6A7sA1J3iwQQzySHgtY12Oo/
This is the lag observed in processing 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.
Note: This histogram was expired from 2022-11-23 to 2023-06-20.
Team: [email protected].
</summary>
</histogram>
<histogram name="Event.Latency.ScrollUpdate.Touch.AverageLagPresentation"
units="pixels" expires_after="2024-12-30">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</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 observed in processing the Gesture Scroll Updates occurring
in the lifetime of a scroll interaction.
Note: This histogram was expired from 2022-12-25 to 2023-06-20.
Team: [email protected].
</summary>
</histogram>
<histogram
name="Event.Latency.ScrollUpdate.Touch.AverageLagPresentation.NoPrediction"
units="pixels" expires_after="2024-12-30">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Measures an average distance that represents how the page sticks to the
finger when user scrolls if prediction was disabled. Only reports touch
scrolling. See
https://docs.google.com/document/d/154jddNiKtxELBvrjLz9v6A7sA1J3iwQQzySHgtY12Oo/
This is the lag observed in processing the Gesture Scroll Updates occurring
in the lifetime of a scroll interaction.
Note: This histogram was expired from 2022-11-23 to 2023-06-12.
Team: [email protected].
</summary>
</histogram>
<histogram
name="Event.Latency.ScrollUpdate.Touch.AverageLagPresentation.RemainingLagPercentage"
units="%" expires_after="2024-12-30">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Percentage of touch lag that prediction wasn't able to remove.
This is the ratio (Lag_with_prediction)/(Lag_without_prediction). Lag is the
average distance between the finger and page positons during touch
scrolling.
0% means all the lag existing before prediction was removed. 100% means that
prediction had no impact. Greater than 100% means that prediction introduced
more lag.
This metric doesn't distinguish between OverPrediction and UnderPrediction.
A same absolute value of OverPrediction or UnderPrediction will result in
the same RemainingLagPercentage value.
Lag_with_prediction =
Event.Latency.ScrollUpdate.Touch.AverageLagPresentation
Lag_without_prediction =
Event.Latency.ScrollUpdate.Touch.AverageLagPresentation.NoPrediction
Note: This histogram was expired from 2022-11-23 to 2023-06-20.
Team: [email protected].
</summary>
</histogram>
<histogram
name="Event.Latency.ScrollUpdate.Touch.AverageLagPresentation.{PredictionImpact}"
units="pixels" expires_after="2024-12-30">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Improvement of prediction in touch lag. It is defined as
(Lag_without_prediction - Lag_with_prediction).
Lag is the distance between the finger position and the rendered position.
When positive, prediction improves touch performance (reduces lag). When
negative, prediction worsens touch performance (increases lag).
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.
This metric uses directionless distances, therefore it doesn't distinguish
between OverPrediction and UnderPrediction. A same absolute value of
OverPrediction or UnderPrediction will result in the same PredictionImpact
value.
Lag_with_prediction =
Event.Latency.ScrollUpdate.Touch.AverageLagPresentation
Lag_without_prediction =
Event.Latency.ScrollUpdate.Touch.AverageLagPresentation.NoPrediction
Note: This histogram was expired from 2022-11-23 to 2023-06-20.
Team: [email protected].
</summary>
<token key="PredictionImpact">
<variant name="PredictionNegative" summary="Negative impact values"/>
<variant name="PredictionPositive" summary="Positive impact values"/>
</token>
</histogram>
<histogram name="Event.MaxDragDistance.{ToolType}" units="dips"
expires_after="never">
<!-- expires-never: Needed for long-term tracking of dragging vs clicking behavior. -->
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The maximum Euclidean distance (in DIPs, device independent pixels) a
single-pointer gesture travels from its starting position during the period
the gesture has been active. The histogram is measured separately for every
pointer type that can be used in gesture recognition: finger, and pen in
drawing/eraser mode. The type names used here follow the corresponding
labels in |MotionEvent.ToolType|.
</summary>
<token key="ToolType">
<variant name="ERASER"/>
<variant name="FINGER"/>
<variant name="STYLUS"/>
</token>
</histogram>
<histogram name="Event.PassiveListeners" enum="EventResultType"
expires_after="2025-02-10">
<owner>[email protected]</owner>
<summary>
The result of handling of MouseWheel, TouchStart, TouchMove, TouchEnd events
in the renderer.
Team: [email protected].
</summary>
</histogram>
<histogram name="Event.ScrollJank.DelayedFramesPercentage.FixedWindow"
units="%" expires_after="never">
<!-- expires-never: guiding metric (internal: go/chrome-browser-guiding-metrics) -->
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
The percentage of frames not presented during a scroll or a fling[1],
meaning frame production took longer than expected and the frame was
skipped.
This metric is different from traditional graphics smoothness metrics as it
considers performance degradation on all threads and processes including
Browser and IO, unlike graphics' smoothness metrics which focus on the core
graphics pipeline (Renderer/GPU).
This metric is only recorded when 64 frames are presented, for example if a
scroll only has 12 frames, the next scroll has 40 frames and the scroll
after has 12 frames, the metric only will be emitted after the 3rd scroll.
This means the last incomplete window might not get reported as the browser
terminates.
For more details about this metric, please check
http://doc/1Y0u0Tq5eUZff75nYUzQVw6JxmbZAW9m64pJidmnGWsY
This histogram is of special interest to the chrome-analysis-team@.
Do not change its semantics or retire it without talking to them first.
[1]Fling is a finger boosted scroll, meaning the screen is moving after the
user has accelerated their finger on the screen and removed it.
</summary>
</histogram>
<histogram name="Event.ScrollJank.DelayedFramesPercentage.PerScroll{Length}"
units="%" expires_after="2025-02-10">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
A frame is deemed janky during a scroll if there was no presented frame in
the previous vsync, and the current frame contains input that was not
presented during the missed frame. Missed input is determined by comparing
the timestamp of the earliest input of the current frame, to that of the
last input of the previously presented frame. If the delta of the timestamps
is less than a vsync + vsync/2, then the input is considered to have been
intended for the missed frame. This metric reports the percentage of delayed
frames within a scroll. This metric gets reported for {Length}.
For more details about this metric, please check
http://doc/1Y0u0Tq5eUZff75nYUzQVw6JxmbZAW9m64pJidmnGWsY
</summary>
<token key="Length" variants="ScrollLength"/>
</histogram>
<histogram name="Event.ScrollJank.MissedVsyncs.PerFrame" units="counts"
expires_after="2025-02-10">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
A frame is deemed janky during a scroll if there was no presented frame in
the previous vsync, and the current frame contains input that was not
presented during the missed frame. Missed input is determined by comparing
the timestamp of the earliest input of the current frame, to that of the
last input of the previously presented frame. If the delta of the timestamps
is less than a vsync + vsync/2, then the input is considered to have been
intended for the missed frame. This metric counts number of vsyncs the frame
was delayed by(which could be zero). The metric gets reported for every
frame.
Please see Event.ScrollJank.MissedVsyncs* for other related histograms
aggregated over a fixed window and emitted once per window.
For more details about this metric, please check
http://doc/1Y0u0Tq5eUZff75nYUzQVw6JxmbZAW9m64pJidmnGWsY
</summary>
</histogram>
<histogram name="Event.ScrollJank.MissedVsyncsPercentage.FixedWindow" units="%"
expires_after="2025-01-26">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
NOTE: This metric is experimental, for performance analysis, please use
Event.ScrollJank.DelayedFramesPercentage.FixedWindow.
A vsync is deemed janky during a scroll if there was no presented frame in
the vsync and the next frame contained late input that was not presented
during the janky vsync. Missed input is determined by comparing the
timestamp of the earliest input of the current frame, to that of the last
input of the previously presented frame. If the delta of the timestamps is
less than a vsync + vsync/2, then the input is considered to have been
intended for the missed frame. This metric reports the percentage of janky
vsyncs within a window of size 64.
For more details about this metric, please check
http://doc/1Y0u0Tq5eUZff75nYUzQVw6JxmbZAW9m64pJidmnGWsY
</summary>
</histogram>
<histogram name="Event.ScrollJank.MissedVsyncsPercentage.PerScroll{Length}"
units="%" expires_after="2025-01-26">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
A vsync is deemed janky during a scroll if there was no presented frame in
the vsync and the next frame contained late input that was not presented
during the janky vsync. Missed input is determined by comparing the
timestamp of the earliest input of the current frame, to that of the last
input of the previously presented frame. If the delta of the timestamps is
less than a vsync + vsync/2, then the input is considered to have been
intended for the missed frame. This metric reports percentage of missed
vsyncs in a scroll in scroll. Metric emits zeros as well i.e. the case when
no frames were delayed. The metric gets reported for {Length}.
Please see Event.ScrollJank.MissedVsyncsPercentage.PerScroll for
unaggregated version of this histogram.
For more details about this metric, please check
http://doc/1Y0u0Tq5eUZff75nYUzQVw6JxmbZAW9m64pJidmnGWsY
</summary>
<token key="Length" variants="ScrollLength"/>
</histogram>
<histogram name="Event.ScrollJank.MissedVsyncs{Operator}.FixedWindow"
units="counts" expires_after="2025-01-26">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
A frame is deemed janky during a scroll if there was no presented frame in
the previous vsync, and the current frame contains input that was not
presented during the missed frame. Missed input is determined by comparing
the timestamp of the earliest input of the current frame, to that of the
last input of the previously presented frame. If the delta of the timestamps
is less than a vsync + vsync/2, then the input is considered to have been
intended for the missed frame. This metric reports the {Operator} in window
of size 64. Metric emits zeros as well i.e. the case when no frames were
delayed.
Please see Event.ScrollJank.MissedVsyncs.PerFrame for unaggregated version
of this histogram.
For more details about this metric, please check
http://doc/1Y0u0Tq5eUZff75nYUzQVw6JxmbZAW9m64pJidmnGWsY
</summary>
<token key="Operator" variants="ScrollJankOperator"/>
</histogram>
<histogram name="Event.ScrollJank.MissedVsyncs{Operator}.FixedWindow2"
units="counts" expires_after="2025-02-10">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
NOTE: This metric is experimental, for performance analysis, please use
Event.ScrollJank.MissedVsyncs{Operator}.FixedWindow.
A vsync is deemed janky during a scroll if there was no presented frame in
the vsync and the next frame contained late input that was not presented
during the janky vsync. Missed input is determined by comparing the
timestamp of the earliest input of the current frame, to that of the last
input of the previously presented frame. If the delta of the timestamps is
less than a vsync + vsync/2, then the input is considered to have been
intended for the missed frame. This metric reports the {Operator} in window
of size 64. Metric emits zeros as well i.e. the case when no frames were
delayed.
For more details about this metric, please check
http://doc/1Y0u0Tq5eUZff75nYUzQVw6JxmbZAW9m64pJidmnGWsY
</summary>
<token key="Operator" variants="ScrollJankOperator"/>
</histogram>
<histogram name="Event.ScrollJank.MissedVsyncs{Operator}.PerScroll{Length}"
units="counts" expires_after="2025-01-26">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
A frame is deemed janky during a scroll if there was no presented frame in
the previous vsync, and the current frame contains input that was not
presented during the missed frame. Missed input is determined by comparing
the timestamp of the earliest input of the current frame, to that of the
last input of the previously presented frame. If the delta of the timestamps
is less than a vsync + vsync/2, then the input is considered to have been
intended for the missed frame. This metric reports the {Operator} in scroll.
Metric emits zeros as well i.e. the case when no frames were delayed. The
metric gets reported for {Length}.
Please see Event.ScrollJank.MissedVsyncs.PerFrame for unaggregated version
of this histogram.
For more details about this metric, please check
http://doc/1Y0u0Tq5eUZff75nYUzQVw6JxmbZAW9m64pJidmnGWsY
</summary>
<token key="Operator" variants="ScrollJankOperator"/>
<token key="Length" variants="ScrollLength"/>
</histogram>
<histogram name="Event.Touch.TimedOutOnDesktopSite" enum="BooleanTimedOut"
expires_after="2023-10-31">
<owner>[email protected]</owner>
<owner>[email protected]</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.
Warning: This histogram has incomplete data. It expired on 2021-08-15 and
then got re-enabled on M110.
Team: [email protected].
</summary>
</histogram>
<histogram name="Event.Touch.TimedOutOnMobileSite" enum="BooleanTimedOut"
expires_after="2023-10-31">
<owner>[email protected]</owner>
<owner>[email protected]</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.
Warning: This histogram has incomplete data. It expired on 2021-08-15 and
then got re-enabled on M110.
Team: [email protected].
</summary>
</histogram>
<histogram name="Event.UserActivation.TriggerFor{ActivationGatedApiType}"
enum="UserActivationTriggerEnum" expires_after="2023-09-30">
<owner>[email protected]</owner>
<owner>[email protected]</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="EventLatency.GestureScrollUpdate.Touchscreen.TotalLatency"
units="microseconds" expires_after="never">
<!-- expires-never: guiding metric (internal: go/chrome-browser-guiding-metrics) -->
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
When a user performs a scroll using touchscreen, a sequence of touch-move
events are generated leading to a sequence of gesture-scroll-update events.
This metric measures total latency of those gesture-scroll-update events
excluding the first one in the sequence and those that are inertial (i.e.
generated as a result of a user fling). Total latency means the time from
when the touch-move causing a gesture-scroll-update is generated until when
the changes caused by the event are successfully presented on the screen.
This histogram will eventually be replaced by its TotalLatency2 equivalent
which uses an improved bucketing.
This histogram only records metrics on machines with high-resolution clocks.
</summary>
</histogram>
<histogram name="EventLatency.GestureScrollUpdate.Touchscreen.TotalLatency2"
units="microseconds" expires_after="2025-01-26">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
When a user performs a scroll using touchscreen, a sequence of touch-move
events are generated leading to a sequence of gesture-scroll-update events.
This metric measures total latency of those gesture-scroll-update events
excluding the first one in the sequence and those that are inertial (i.e.
generated as a result of a user fling). Total latency means the time from
when the touch-move causing a gesture-scroll-update is generated until when
the changes caused by the event are successfully presented on the screen.
This histogram is similar to its TotalLatency (non-v2) equivalent except
that it uses an improved bucketing. We will eventually remove the non-v2
version.
This histogram only records metrics on machines with high-resolution clocks.
</summary>
</histogram>
<histogram
name="EventLatency.GestureScrollUpdate.{NonTouchscreenScrollInputType}.TotalLatency2"
units="microseconds" expires_after="2025-01-26">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Tracks total latency of {NonTouchscreenScrollInputType}
gesture-scroll-update events that are non-inertial (i.e. not generated due
to a user fling) and not the first one in a scroll sequence, from when the
user input causing the event is performed until the frame caused by the
event is submitted by the GPU service and presented successfully on the
screen.
This histogram only records metrics on machines with high-resolution clocks.
</summary>
<token key="NonTouchscreenScrollInputType">
<variant name="Autoscroll" summary="autoscroll"/>
<variant name="Scrollbar" summary="scrollbar"/>
<variant name="Wheel" summary="mouse wheel or touchpad"/>
</token>
</histogram>
<histogram name="EventLatency.TotalLatency" units="microseconds"
expires_after="2025-02-10">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Tracks total latency of all event types, from when the user input causing
the event is performed until the frame caused by the event is submitted by
the GPU service and presented successfully on the screen.
This histogram only records metrics on machines with high-resolution clocks.
</summary>
</histogram>
<histogram
name="EventLatency.{NonGsuScrollEventType}.{ScrollInputType}.TotalLatency2"
units="microseconds" expires_after="2025-02-10">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Tracks total latency of {ScrollInputType} {NonGsuScrollEventType}, from when
the user input causing the event is performed until the frame caused by the
event is submitted by the GPU service and presented successfully on the
screen.
This histogram only records metrics on machines with high-resolution clocks.
</summary>
<token key="NonGsuScrollEventType">
<variant name="FirstGestureScrollUpdate"
summary="gesture-scroll-update events that are the first one in a
scroll sequence"/>
<variant name="GestureScrollBegin"
summary="gesture-scroll-begin event. These are rarely handled, as
most user initiated scrolls will start with
FirstGestureScrollUpdate. Which was added to match the
legacy
Event.Latency.ScrollUpdate.Touch.TimeToScrollUpdateSwapBegin4.
This tracks GestureScrollBegin"/>
<variant name="GestureScrollEnd" summary="gesture-scroll-end events"/>
<variant name="InertialGestureScrollUpdate"
summary="gesture-scroll-update events that are inertial (i.e.
generated due to a user fling)"/>
</token>
<token key="ScrollInputType">
<variant name="Autoscroll" summary="autoscroll"/>
<variant name="Scrollbar" summary="scrollbar"/>
<variant name="Touchscreen" summary="touchscreen"/>
<variant name="Wheel" summary="mouse wheel or touchpad"/>
</token>
</histogram>
<histogram name="EventLatency.{NonScrollPinchEventType}.TotalLatency"
units="microseconds" expires_after="2025-01-26">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Tracks total latency of {NonScrollPinchEventType}, from when the user input
causing the event is performed generated until the frame caused by the event
is submitted by the GPU service and presented successfully on the screen.
This histogram only records metrics on machines with high-resolution clocks.
</summary>
<token key="NonScrollPinchEventType">
<variant name="GestureDoubleTap" summary="gesture-double-tap events"/>
<variant name="GestureLongPress" summary="gesture-long-press events"/>
<variant name="GestureLongTap" summary="gesture-long-tap events"/>
<variant name="GestureShowPress" summary="gesture-show-press events"/>
<variant name="GestureTap" summary="gesture-tap events"/>
<variant name="GestureTapCancel" summary="gesture-tap-cancel events"/>
<variant name="GestureTapDown" summary="gesture-tap-down events"/>
<variant name="GestureTapUnconfirmed"
summary="gesture-tap-unconfirmed events"/>
<variant name="GestureTwoFingerTap"
summary="gesture-two-finger-tap events"/>
<variant name="KeyPressed" summary="key-pressed events"/>
<variant name="KeyReleased" summary="key-released events"/>
<variant name="MouseDragged" summary="mouse-dragged events"/>
<variant name="MouseMoved" summary="mouse-moved events"/>
<variant name="MousePressed" summary="mouse-pressed events"/>
<variant name="MouseReleased" summary="mouse-released events"/>
<variant name="MouseWheel" summary="mouse-wheel events"/>
<variant name="TouchMoved" summary="touch-moved events"/>
<variant name="TouchPressed" summary="touch-pressed events"/>
<variant name="TouchReleased" summary="touch-released events"/>
</token>
</histogram>
<histogram name="EventLatency.{PinchEventType}.{PinchInputType}.TotalLatency"
units="microseconds" expires_after="2025-02-10">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Tracks total latency of {PinchInputType} {PinchEventType}, from when the
user input causing the event is performed until the frame caused by the
event is submitted by the GPU service and presented successfully on the
screen.
This histogram only records metrics on machines with high-resolution clocks.
</summary>
<token key="PinchEventType">
<variant name="GesturePinchBegin" summary="gesture-pinch-begin events"/>
<variant name="GesturePinchEnd" summary="gesture-pinch-end events"/>
<variant name="GesturePinchUpdate"
summary="gesture-pinch-update events in a scroll sequence"/>
</token>
<token key="PinchInputType">
<variant name="Touchpad" summary="touchpad"/>
<variant name="Touchscreen" summary="touchscreen"/>
</token>
</histogram>
<histogram name="EventLatency.{ScrollEventType}.GenerationToBrowserMain"
units="microseconds" expires_after="2024-12-30">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Tracks latency from when the user input causing the event is generated until
the the event is first processed on the Browser Main Thread. Reported for
{ScrollEventType}.
This histogram only records metrics on machines with high-resolution clocks.
</summary>
<token key="ScrollEventType" variants="ScrollEventType"/>
</histogram>
<histogram name="EventLatency.{ScrollEventType}.TotalLatency2"
units="microseconds" expires_after="2025-01-26">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Tracks total latency of {ScrollEventType}, from when the user input causing
the event is performed generated until the frame caused by the event is
submitted by the GPU service and presented successfully on the screen.
This histogram only records metrics on machines with high-resolution clocks.
</summary>
<token key="ScrollEventType" variants="ScrollEventType"/>
</histogram>
<histogram name="EventLatency.{ScrollEventType}.{DispatchStage}.{RatioType}"
units="%" expires_after="2025-02-10">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Tracks the latency of {ScrollEventType}, as a ratio from {DispatchStage} to
the VSync time. This is normalized by the frame interval. This is reported
when the stage occurs {RatioType}.
</summary>
<token key="ScrollEventType" variants="ScrollEventType"/>
<token key="DispatchStage">
<variant name="ArrivedInRendererVsVSyncRatio"
summary="when the event arrived in the Renderer"/>
<variant name="GenerationVsVsyncRatio"
summary="when the event was generated"/>
</token>
<token key="RatioType">
<variant name="AfterVSync" summary="after the VSync timestamp"/>
<variant name="BeforeVSync" summary="before the VSync timestamp"/>
</token>
</histogram>
<histogram name="EventLatency.{ScrollEventType}.{TopControls}"
units="microseconds" expires_after="2025-02-23">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<summary>
Tracks total latency of {ScrollEventType}, from when the user input causing
the event is performed generated until the frame caused by the event is
submitted by the GPU service and presented successfully on the screen.
This is reported for {TopControls}.
This histogram only records metrics on machines with high-resolution clocks.
</summary>
<token key="ScrollEventType" variants="ScrollEventType"/>
<token key="TopControls">
<variant name="TopControlsDidNotMove"
summary="when Android Top Controls did not move during the scroll.
This is subsampled at a rate of 1:1000 as there is
significantly higher volume of these scrolls."/>
<variant name="TopControlsMoved"
summary="when the Android Top Controls moved during the scroll.
Reported for all such scrolls."/>
</token>
</histogram>
</histograms>
</histogram-configuration>
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