metrics/histograms/histograms_xml/ios/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
found in the LICENSE file.
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<!--
This file is used to generate a comprehensive list of IOS 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="IOS.CommittedNavigationHasContext" enum="Boolean"
    expires_after="2021-09-24">
  <owner>ajuma@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    When a navigation is committed, it should have a non-null NavigationContext.
    This histogram counts the frequency of this invariant holding at the time
    when a new navigation is committed. It is used to verify the effectiveness
    of code fixes because this issue is not currently reproducible in testing
    (http://crbug.com/864769). True means a non-null NavigationContext is
    present.
  </summary>
</histogram>

<histogram name="IOS.CommittedURLMatchesCurrentItem" enum="Boolean"
    expires_after="2021-09-24">
  <owner>ajuma@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    When a navigation is committed, the web view URL is expected to match that
    of the current back-forward item. WKWebView seems to break this assumption
    at times. This histogram counts the frequency of this invariant violation at
    the time when a new navigation is committed. True means the URL matches the
    current back-forward item.
  </summary>
</histogram>

<histogram name="IOS.ContentExtension.DisplayCount" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The number of times the Content Extension was displayed since last Chrome
    foregrounding. Reported when Chrome is put in foregrounded. Note: events
    where the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.ContentExtension.Index" units="index"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The index of the URL selected by the user in the Content Extension.
  </summary>
</histogram>

<histogram name="IOS.ContentRuleListProviderUpdateSuccess"
    enum="BooleanSuccess" expires_after="2020-12-31">
  <owner>rkgibson@google.com</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    When the content rule list provider updates its lists, this can succeed or
    fail. Failure occurs when the rule lists are updated again before the first
    update finishes.
  </summary>
</histogram>

<histogram name="IOS.Cookies.GetCookiesForURLCallResult"
    enum="IOSGetCookiesForURLCallResult" expires_after="2021-08-01">
  <owner>mrefaat@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    Recorded to indicate whether the GetCookiesForURL call found cookies or not
    when called on a specific system cookie store implementation. Most of the
    cookies fetching on iOS Chromium is done by the WKWebView and doesn't
    involve calling GetCookiesForURL. The method is only called when a request
    is made by the UrlRequestFetcher for cases that are not handled by WKWebView
    (eg. Downloads, Auto Suggestions and NTP tiles).
  </summary>
</histogram>

<histogram name="IOS.Cookies.GetCookiesForURLCallStoreType"
    enum="IOSGetCookiesForURLCallCookieStoreType" expires_after="2021-08-01">
  <owner>mrefaat@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    The system cookie store type used when GetCookiesForURL method is called.
    Most of the cookies fetching on iOS Chromium is done by the WKWebView and
    doesn't involve calling GetCookiesForURL. The method is only called when a
    request is made by the UrlRequestFetcher for cases that are not handled by
    WKWebView (eg. Downloads, Auto Suggestions and NTP tiles).
  </summary>
</histogram>

<histogram name="IOS.CredentialExtension.CopyPasswordCount" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The number of times the Credential Extension user copied a Password since
    last Chrome foregrounding. Reported when Chrome is put in foreground. Note:
    events where the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.CredentialExtension.CopyURLCount" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The number of times the Credential Extension user copied a URL since last
    Chrome foregrounding. Reported when Chrome is put in foreground. Note:
    events where the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.CredentialExtension.CopyUsernameCount" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The number of times the Credential Extension user copied a Username since
    last Chrome foregrounding. Reported when Chrome is put in foreground. Note:
    events where the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.CredentialExtension.DisplayCount" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The number of times the Credential Extension was displayed since last Chrome
    foregrounding. Reported when Chrome is put in foreground. Note: events where
    the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.CredentialExtension.FetchPasswordFailure" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The number of times the Credential Extension password util failed to look up
    for a password since last Chrome foregrounding. Reported when Chrome is put
    in foreground. Note: events where the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.CredentialExtension.FetchPasswordNilArgument"
    units="count" expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The number of times the Credential Extension pasword util was queried with a
    nil argument since last Chrome foregrounding. Reported when Chrome is put in
    foreground. Note: events where the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.CredentialExtension.PasswordUseCount" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The number of times the Credential Extension user selected for a Password
    since last Chrome foregrounding. Reported when Chrome is put in foreground.
    Note: events where the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.CredentialExtension.QuickPasswordUseCount" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The number of times the Credential Extension selected a Password without
    user intervention since last Chrome foregrounding. Reported when Chrome is
    put in foreground. Note: events where the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.CredentialExtension.ReauthCount" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The number of times the Credential Extension needed user reauthentication
    since last Chrome foregrounding. Reported when Chrome is put in foreground.
    Note: events where the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.CredentialExtension.SearchCount" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The number of times the Credential Extension user searched for a Password
    since last Chrome foregrounding. Reported when Chrome is put in foreground.
    Note: events where the count is zero were removed in M91.
  </summary>
</histogram>

<histogram
    name="IOS.CredentialExtension.Service.Error.ReplaceCredentialIdentitiesWithIdentities"
    enum="iOSCredentialIdentityStoreErrorForReporting"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    Recorded when a request to replace identities in ASCredentialIdentityStore
    fails.
  </summary>
</histogram>

<histogram name="IOS.CredentialExtension.ShowPasswordCount" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The number of times the Credential Extension user unobfuscated a Password
    since last Chrome foregrounding. Reported when Chrome is put in foreground.
    Note: events where the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.CriticalActionBackgroundTimeRemaining" units="ms"
    expires_after="2021-05-30">
  <obsolete>
    Recording removed 12/2020.
  </obsolete>
  <owner>justincohen@chromium.org</owner>
  <summary>
    Recorded when app is running in the background and posted a background task.
    This time is obtained by calling UIApplication.backgroundTimeRemaining. When
    backgroundTimeRemaining reaches 0 and there is at least one running
    background task, then iOS terminates the app instead of suspending it. The
    lower recorded value is, the higher chances that posted task will keep
    running when backgroundTimeRemaining reaches 0, causing the app termination.
    When app is relaunched after termination the app starts cold which is slower
    and does not fully restore the prior UI state, so terminations are worse
    than suspensions.
  </summary>
</histogram>

<histogram name="IOS.CRWWKNavigationStatesRemoveOldPending" enum="Boolean"
    expires_after="2021-06-14">
  <owner>justincohen@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    Workaround for a WKWebView bug where WKNavigations can leak, leaving a
    permanent pending URL, thus breaking the omnibox. While it is possible for
    navigations to finish out-of-order, it's an edge case that should be handled
    gracefully, as last committed will appear in the omnibox instead of the
    pending URL. This metric records whether there are old navigations to clean
    up each time a navigation finishes. See crbug.com/1010765 for details.
  </summary>
</histogram>

<histogram name="IOS.DefaultBrowserFullscreenPromo"
    enum="IOSDefaultBrowserFullscreenPromoAction" expires_after="2022-02-01">
  <owner>thegreenfrog@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>
    The action taken by the user in response to the default browser promo.
  </summary>
</histogram>

<histogram name="IOS.DefaultBrowserFullscreenPromoRemindMe"
    enum="IOSDefaultBrowserFullscreenPromoAction" expires_after="2021-09-05">
  <owner>thegreenfrog@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>
    The action taken by the user in response to the default browser promo with
    the Remind Me Later button.
  </summary>
</histogram>

<histogram name="IOS.DefaultBrowserFullscreenPromoRemindMeSecondPromo"
    enum="IOSDefaultBrowserFullscreenPromoAction" expires_after="2021-10-10">
  <owner>thegreenfrog@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>
    The action taken by the user in response to the second default browser promo
    after tapping on the Remind Me Later button.
  </summary>
</histogram>

<histogram name="IOS.DefaultBrowserFullscreenTailoredPromoAllTabs"
    enum="IOSDefaultBrowserFullscreenPromoAction" expires_after="2022-02-01">
  <owner>javierrobles@chromium.org</owner>
  <owner>rkgibson@chromium.org</owner>
  <summary>
    The action taken by the user in response to the &quot;All tabs&quot; default
    browser tailored promo.
  </summary>
</histogram>

<histogram name="IOS.DefaultBrowserFullscreenTailoredPromoMadeForIOS"
    enum="IOSDefaultBrowserFullscreenPromoAction" expires_after="2022-02-01">
  <owner>javierrobles@chromium.org</owner>
  <owner>rkgibson@chromium.org</owner>
  <summary>
    The action taken by the user in response to the &quot;Made for iOS&quot;
    default browser tailored promo.
  </summary>
</histogram>

<histogram name="IOS.DefaultBrowserFullscreenTailoredPromoStaySafe"
    enum="IOSDefaultBrowserFullscreenPromoAction" expires_after="2022-02-01">
  <owner>javierrobles@chromium.org</owner>
  <owner>rkgibson@chromium.org</owner>
  <summary>
    The action taken by the user in response to the &quot;Stay Safe&quot;
    default browser tailored promo.
  </summary>
</histogram>

<histogram name="IOS.DefaultBrowserPromo.TailoredFullscreen.{Action}"
    enum="IOSDefaultBrowserTailoredPromoType" expires_after="2022-04-20">
  <owner>javierrobles@chromium.org</owner>
  <owner>rkgibson@chromium.org</owner>
  <summary>
    Logged when the {Action} action happens in a tailored default browser promo.
    Records the type of promo.
  </summary>
  <token key="Action">
    <variant name="Accepted"/>
    <variant name="Appear"/>
    <variant name="Dismiss"/>
  </token>
</histogram>

<histogram name="IOS.Dialogs.JavaScriptDialogClosed"
    enum="IOSJavaScriptDialogDismissalCause" expires_after="M80">
  <owner>kkhorimoto@chromium.org</owner>
  <owner>michaeldo@chromium.org</owner>
  <summary>Tracks the way JavaScript dialogs are closed on iOS.</summary>
</histogram>

<histogram name="IOS.DragAndDrop.DragContent" enum="DragContent"
    expires_after="2020-03-01">
  <obsolete>
    Removed 12/2020 as it is no longer needed for analysis.
  </obsolete>
  <owner>jif@chromium.org</owner>
  <summary>
    The type of content that the user is dragging into Chrome. Because a drag
    can contain multiple types of objects, multiple DragContent values may be
    recorded for a single drag event.
  </summary>
</histogram>

<histogram name="IOS.EnterTabSwitcherSnapshotResult"
    enum="EnterTabSwitcherSnapshotResult" expires_after="2021-08-01">
  <owner>edchin@chromium.org</owner>
  <owner>justincohen@chromium.org</owner>
  <summary>
    Tracks the result of snapshotting when the user enters the tab switcher.
    Recorded whenever the user enters the tab switcher.
  </summary>
</histogram>

<histogram name="IOS.FinishedNavigationHasContext" enum="Boolean"
    expires_after="2019-05-01">
  <owner>gambard@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    When a navigation is finished, it should have a non-null NavigationContext.
    This histogram counts the frequency of this invariant holding at the time
    when a new navigation is finished. It is used to verify the effectiveness of
    code fixes because this issue is not currently reproducible in testing
    (http://crbug.com/864769). True means a non-null NavigationContext is
    present.
  </summary>
</histogram>

<histogram name="IOS.FinishedNavigationHasItem" enum="Boolean"
    expires_after="2019-05-01">
  <owner>gambard@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    When a navigation is finished, it should have a non-null NavigationItem.
    This histogram counts the frequency of this invariant holding at the time
    when a new navigation is finished. It is used to verify the effectiveness of
    code fixes because this issue is not currently reproducible in testing
    (http://crbug.com/864769). True means a non-null NavigationItem is present.
  </summary>
</histogram>

<histogram name="IOS.FinishedURLMatchesCurrentItem" enum="Boolean"
    expires_after="2021-10-26">
  <owner>ajuma@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    When a navigation is finished, the web view URL is expected to match that of
    the current back-forward item. WKWebView seems to break this assumption at
    times. This histogram counts the frequency of this invariant violation at
    the time when a new navigation is finished. True means the URL matches the
    current back-forward item.
  </summary>
</histogram>

<histogram name="IOS.FormInputAccessory.ExecuteFormAssistActionException"
    enum="FormInputAccessoryAction" expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>
    Reports exceptions when trying to send a form input accessory action to the
    virtual keyboard.
  </summary>
</histogram>

<histogram name="IOS.Handoff.Origin" enum="IOSHandoffOrigin"
    expires_after="M77">
  <owner>erikchen@chromium.org</owner>
  <summary>
    This event is recorded each time a Handoff is received by Chrome on iOS. The
    enumeration indicates the source of the Handoff.
  </summary>
</histogram>

<histogram name="IOS.Incognito.TimeSpent" units="ms" expires_after="2021-09-12">
  <owner>olivierrobin@chromium.org</owner>
  <owner>thegreenfrog@chromium.org</owner>
  <summary>
    The time incognito profile is displayed to the user. Incognito sessions
    during less than 10 seconds are not reported. Incognito session paused for
    less than 10 seconds is resumed.
  </summary>
</histogram>

<histogram name="IOS.IPHBubbleDismissalReason" enum="BubbleDismissalReason"
    expires_after="M77">
  <obsolete>
    Deprecated 12/2020 as it is no longer used for analysis.
  </obsolete>
  <owner>pkl@chromium.org</owner>
  <summary>
    Tracks the reason for why the In Product Help bubble was dismissed.
  </summary>
</histogram>

<histogram name="IOS.IsDefaultBrowser" enum="Boolean" expires_after="never">
<!-- expires-never: used internally for filtering -->

  <owner>thegreenfrog@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <owner>chrome-metrics-team@google.com</owner>
  <summary>
    As of iOS14, users will be able to set a default browser other than Safari.
    When Chrome is the default browser, it will receive all URL opens, which is
    likely to change certain stability metrics. Thus, it will be good to filter
    those metrics by default browser status. This metrics records whether the
    user was deemed to have set Chrome as the device's default browser. This
    metric will be logged once per metrics log upload.
  </summary>
</histogram>

<histogram name="IOS.IsEligibleDefaultBrowserPromoUser" enum="BooleanEligible"
    expires_after="2021-09-21">
  <owner>thegreenfrog@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>
    This metric reports whether the user was deemed eligible to be shown default
    browser fullscreen promos. Eligibility currently includes signed-in users,
    external intent app opens, clipboard copies, and GrowthKit opens. This
    metric will be logged once per metrics log upload.
  </summary>
</histogram>

<histogram name="IOS.JavascriptContentBlockFailure"
    enum="IOSJavascriptContentBlockType" expires_after="2020-12-31">
  <owner>rkgibson@google.com</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    IOS Content Blocking uses special injected Javascript to block access to
    things like cookies and local storage. Future changes to iOS/WebKit could
    cause these blocks to break. This logs that occurrence.
  </summary>
</histogram>

<histogram name="IOS.LinkToText.ShouldOfferResult"
    enum="LinkToTextShouldOfferResult" expires_after="2021-12-01">
  <owner>tmartino@chromium.org</owner>
  <owner>seblalancette@chromium.org</owner>
  <summary>
    The result of conditional disable/enable checking for the Link to Text
    feature, including granular failure reasons when the feature is not offered.
  </summary>
</histogram>

<histogram name="IOS.LocationPermissions.FirstRunModal.Interaction"
    enum="LocationPermissionsFirstRunModalIOSEnum" expires_after="2021-10-04">
  <owner>thegreenfrog@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>
    The user engagement of the Location permissions first run modal.
  </summary>
</histogram>

<histogram name="IOS.LocationPermissionsUI" enum="LocationPermissionsIOSUI"
    expires_after="2021-10-04">
  <owner>thegreenfrog@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>
    The user was shown an arm of the location permissions experiment. Recorded
    when the user is shown the UI of an experiment arm. Not recorded for the
    control arm.
  </summary>
</histogram>

<histogram name="IOS.MainThreadFreezeDetection.NotRunningAfterReport"
    enum="IOSMainThreadFreezeDetectionNotRunningAfterReportBlock"
    expires_after="2021-09-12">
  <owner>justincohen@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    Recorded when the main thread recovers immediately after a freeze report was
    generated.
  </summary>
</histogram>

<histogram name="IOS.MainThreadFreezeDetection.RecoveredAfter" units="ms"
    expires_after="2021-11-12">
  <owner>justincohen@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The time during which main thread was not responding. 0 if application was
    killed before recovering. Logged after an action posted on the main thread
    is not executed immediately. The histogram is sent when the task is finally
    executed or on next application startup.
  </summary>
</histogram>

<histogram name="IOS.MetricKit.ApplicationHangTime" units="ms"
    expires_after="2021-09-15">
  <owner>justincohen@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The durations of time in which the app is too busy to handle user
    interaction responsively. Logged when a MXMetricPayload is received (one per
    day). Each sample correspond to one hang. Minimum observed hang time is
    250ms (but this value may change in future device/OS version). This metric
    can be normalized by comparing the total number of hangs or the total time
    spent hung against the number of clients emitting to
    IOS.MetricKit.ForegroundTimePerDay (hangs per users) or against the total
    time reported by IOS.MetricKit.ForegroundTimePerDay (hangs per usage).
    ApplicationHangTime and ForegroundTimePerDay have the same restrictions
    about when they're emitted (iOS 13+, opted-in to share diagnostic data,
    etc.). Further, as hangs can only happen during foreground use,
    ForegroundTimePerDay makes a good comparison point. Only freezes in browser
    process are reported.

    Recorded only if user opted in for sharing diagnostic data on iOS device.
    Note: The date the data is reported is later than the day it account for.
  </summary>
</histogram>

<histogram name="IOS.MetricKit.ApplicationResumeTime" units="ms"
    expires_after="2021-09-12">
  <owner>justincohen@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The amount of time taken to resume the app from the background (not
    aggregated). Logged when a MXMetricPayload is received (one per day).

    Recorded only if user opted in for sharing diagnostic data on iOS device.
    Note: The date the data is reported is later than the day it account for.
  </summary>
</histogram>

<histogram name="IOS.MetricKit.AverageSuspendedMemory" units="MB"
    expires_after="2021-10-31">
  <owner>justincohen@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The average amount of memory in use by the app when it's suspended. Averaged
    on a 24 hours period. Logged when a MXMetricPayload is received (one per
    day).

    Recorded only if user opted in for sharing diagnostic data on iOS device.
    Note: The date the data is reported is later than the day it account for.
  </summary>
</histogram>

<histogram name="IOS.MetricKit.BackgroundExitData" enum="MetricKitExitData"
    expires_after="2021-09-12">
  <owner>justincohen@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The reason for the application termination in background. Recorded when a
    MXMetricPayload is received from the OS (at most once per day) at
    unspecified time. Records cumulative data collected and agregated since the
    previous recording. All buckets from MetricKitExitData are available on iOS
    14 and higher (unless MetricKitExitData bucket comments specify otherwise).

    Note that crashes while in the background are not considered crashes /
    unclean shutdowns in UMA stability metrics. This is because the
    &quot;CleanExitBeacon&quot; is set when Chrome is put in the background.

    Recorded only if user opted in for sharing diagnostic data on iOS device.
    Note: The date the data is reported is later than the day it account for.
  </summary>
</histogram>

<histogram name="IOS.MetricKit.BackgroundTimePerDay" units="ms"
    expires_after="2021-10-04">
  <owner>justincohen@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The total time the app is in the background. Logged when a MXMetricPayload
    is received (one per day). This correspond as Chrome running but not having
    active scene (i.e. the application just has been backgrounded or is doing
    background activity like background music or picture in picture).

    Recorded only if user opted in for sharing diagnostic data on iOS device.
    Note: The date the data is reported is later than the day it account for.
  </summary>
</histogram>

<histogram name="IOS.MetricKit.ForegroundExitData" enum="MetricKitExitData"
    expires_after="never">
<!-- expires-never: guiding metric (internal: go/chrome-browser-guiding-metrics) -->

  <owner>justincohen@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <owner>chrome-analysis-team@google.com</owner>
  <summary>
    The reason for the application termination in foreground. Recorded when a
    MXMetricPayload is received from the OS (at most once per day) at
    unspecified time. Records cumulative data collected and agregated since the
    previous recording. All buckets from MetricKitExitData are available on iOS
    14 and higher (unless MetricKitExitData bucket comments specify otherwise).
    All buckets except &quot;App exited normally&quot; are likely user-visible
    terminations (this is a guess rather that verified fact).

    Application is in foreground is at least one scene is active in foreground.
    Picture in picture and background music playing are not considered as
    foreground.

    Recorded only if user opted in for sharing diagnostic data on iOS device.
    Note: The date the data is reported is later than the day it account for.

    This histogram is of special interest to the chrome-analysis-team@. Do not
    change its semantics or retire it without talking to them first.
  </summary>
</histogram>

<histogram name="IOS.MetricKit.ForegroundTimePerDay" units="s"
    expires_after="2021-09-19">
  <owner>justincohen@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The total time the app is in the foreground, aggregated over all foreground
    interactions since the last time this metric was reported. This is at most a
    24 hour period. Logged when a MXMetricPayload is received (one per day).

    Application is in foreground is at least one scene is active in foreground.
    Picture in picture and background music playing are not considered as
    foreground

    Recorded only if user opted in for sharing diagnostic data on iOS device.
    Note: The date the data is reported is later than the day it account for.
  </summary>
</histogram>

<histogram name="IOS.MetricKit.PeakMemoryUsage" units="MB"
    expires_after="2021-09-19">
  <owner>justincohen@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The largest amount of memory used by the app since the last time this metric
    was reported. This is at most a 24 hour period. Logged when a
    MXMetricPayload is received (one per day).

    Because this implemented by Apple, we do not know how peak memory usage is
    identified (by polling?). We also do not know if this covers background
    usage. We also do not know if the period only includes background usage
    whether this is going to be reported.

    Recorded only if user opted in for sharing diagnostic data on iOS device.
    Note: The date the data is reported is later than the day it account for.
  </summary>
</histogram>

<histogram name="IOS.MetricKit.TimeToFirstDraw" units="ms"
    expires_after="2021-09-19">
  <owner>justincohen@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The amount of time taken to launch the app. Logged when a MXMetricPayload is
    received (one per day).

    Recorded only if user opted in for sharing diagnostic data on iOS device.
    Note: The date the data is reported is later than the day it account for.
  </summary>
</histogram>

<histogram name="IOS.MultiWindow.Configuration"
    enum="IOSMultiWindowConfiguration" expires_after="2021-06-30">
  <owner>marq@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>MultiWindow configration sampled once per minute.</summary>
</histogram>

<histogram name="IOS.MultiWindow.OpenInNewWindow" enum="WindowActivityOrigin"
    expires_after="2021-08-29">
  <owner>marq@chromium.org</owner>
  <owner>djean@chromium.org</owner>
  <summary>
    The source of &quot;Open in new Window&quot; user requests. Recorded when a
    newly created window is added to a session.
  </summary>
</histogram>

<histogram name="IOS.NSString.stringByReplacingCharactersInRange.NilArgument"
    enum="Boolean" expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>
    NSString API: stringByReplacingCharactersInRange:withString: was invoked
    with a nil argument.
  </summary>
</histogram>

<histogram name="IOS.NTP.Impression" enum="IOSNTPImpression"
    expires_after="2021-09-12">
  <owner>gambard@chromium.org</owner>
  <summary>
    The type of NTP impressions on iOS, split by type of suggestions shown
    (local vs remote vs remote_collapsed).
  </summary>
</histogram>

<histogram name="IOS.OpenIn.DownloadResult" enum="IOSOpenInDownloadResult"
    expires_after="2021-10-10">
  <owner>mrefaat@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    The result of the download operation done when the user taps &quot;open
    in&quot; button to open a file by a different application.
  </summary>
</histogram>

<histogram name="IOS.OpenIn.MimeType" enum="IOSOpenInMimeType"
    expires_after="2021-09-19">
  <owner>ewannpv@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    The MIME type of the previwed file when the &quot;Open In&quot; toolbar is
    presented.
  </summary>
</histogram>

<histogram name="IOS.PageLoadCount.Counts"
    enum="IOSPageLoadCountNavigationType" expires_after="2021-10-17">
  <owner>gambard@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>The number of navigation started events by navigation type.</summary>
</histogram>

<histogram name="IOS.PageLoadCount.LoadingStarted" units="units"
    expires_after="2021-08-22">
  <owner>gambard@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    The &quot;true&quot; value of this boolean histogram counts the number of
    page loading started events. The &quot;false&quot; value will never be seen.
  </summary>
</histogram>

<histogram name="IOS.PageLoadedSnapshotResult" enum="PageLoadedSnapshotResult"
    expires_after="2021-08-01">
  <owner>edchin@chromium.org</owner>
  <owner>justincohen@chromium.org</owner>
  <summary>
    Tracks the result of snapshotting when the page has been loaded.
  </summary>
</histogram>

<histogram name="IOS.PageLoadTiming.OmnibarToPageLoaded" units="ms"
    expires_after="2021-09-22">
  <owner>ajuma@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    Measures the time from the end of user input in the omnibox to when the page
    is fully loaded. Only measures page loads initiated by user typing a URL or
    selecting a suggested entry from the URL bar.
  </summary>
</histogram>

<histogram name="IOS.Reauth.Password.Autofill" enum="ReauthenticationEvent"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>sarraf@google.com</owner>
  <summary>
    Tracks the results and attempts of reauthentication when using password
    Autofill suggestions.
  </summary>
</histogram>

<histogram name="IOS.Reauth.Password.ManualFallback"
    enum="ReauthenticationEvent" expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>sarraf@google.com</owner>
  <summary>
    Tracks the results and attempts of reauthentication when using a password in
    Manual Fallback.
  </summary>
</histogram>

<histogram name="IOS.RepeatedExternalAppPromptResponse"
    enum="IOSRepeatedExternalAppPromptResponse" expires_after="2021-08-01">
  <owner>mrefaat@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    The user reaction to the prompt that appears when a website tries to open an
    external application repeatedly.
  </summary>
</histogram>

<histogram name="IOS.RestoreNavigationItemCount" units="rank"
    expires_after="2021-09-05">
  <owner>gambard@chromium.org</owner>
  <owner>justincohen@chromium.org</owner>
  <summary>
    [iOS] The number of items Navigation Manager was requested to restore. 100
    is logged when the number of navigation items is greater than 100. This is
    just a requested count and actual number of restored items can be smaller.
    Restoration is triggered in the following cases (the list is not
    exhaustive): app cold start, remote tab was open, cookie were cleared,
    recently closed tab was restored.
  </summary>
</histogram>

<histogram name="IOS.RestoreNavigationTime" units="ms"
    expires_after="2021-09-05">
  <owner>gambard@chromium.org</owner>
  <owner>justincohen@chromium.org</owner>
  <summary>
    [iOS] Time spent on restoring committed Navigation Manager's items. Recorded
    once per restoration, as a cumulative time across all items. Restoration is
    triggered in the following cases (the list is not exhaustive): app cold
    start, remote tab was open, cookies were cleared, recently closed tab was
    restored. This metric will be used for monitoring session restoration
    performance which relies on system's WKWebView.
  </summary>
</histogram>

<histogram name="IOS.SafeBrowsing.RedirectedRequestResponseHostsMatch"
    enum="BooleanMatched" expires_after="2021-11-06">
  <owner>ajuma@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    The URL in a navigation request should have the same host as the URL in the
    corresponding response, but this sometimes doesn't hold after a server
    redirect because of a WKWebView bug. This histogram counts the frequency of
    this invariant violation, and is logged each time that a main-frame
    navigation response is received after a server redirect. True means that the
    request and response URLs have the same host.
  </summary>
</histogram>

<histogram name="IOS.SearchExtension.Action" enum="IOSSearchExtensionAction"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>The action selected by the user in the Search Extension.</summary>
</histogram>

<histogram name="IOS.SearchExtension.DisplayCount" units="count"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The number of times the Search Extension was displayed since last Chrome
    foregrounding. Reported when Chrome is put in foreground. Note: events where
    the count is zero were removed in M91.
  </summary>
</histogram>

<histogram name="IOS.SessionMigration" enum="IOSSessionMigration"
    expires_after="2021-12-11">
  <owner>mrefaat@chromium.org</owner>
  <owner>sdefresne@chromium.org</owner>
  <summary>
    Record whether the session (list of tabs, and their snapshots) was migrated
    from one place to another. This migration can happen when the user update
    Chrome, their device version of iOS or when they restore a backup. The event
    is recorded for all Browser creation, so most of the event should be
    &quot;No Migration&quot;.
  </summary>
</histogram>

<histogram name="IOS.ShareExtension.ReceivedEntriesCount" units="files"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The number of items received simultaneously in Chrome from the IOS share
    extension.
  </summary>
</histogram>

<histogram name="IOS.ShareExtension.ReceivedEntry"
    enum="IOSShareExtensionReceivedEntryType" expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>Type of the item received from the iOS share extension.</summary>
</histogram>

<histogram name="IOS.ShareExtension.ReceivedEntryDelay" units="ms"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The delay in milliseconds between the item creation in the extension and its
    processing in Chrome.
  </summary>
</histogram>

<histogram name="IOS.ShareExtension.Source"
    enum="IOSShareExtensionReceivedEntrySource" expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    The source application that sent the external command to Chrome.
  </summary>
</histogram>

<histogram name="IOS.SharePageLatency" units="ms" expires_after="M77">
  <obsolete>
    Deprecated 12/2020 as it is no longer used for analysis.
  </obsolete>
  <owner>pkl@chromium.org</owner>
  <summary>
    The latency in milliseconds between the start of the Share Page operation
    and when the UI is ready to be presented.
  </summary>
</histogram>

<histogram name="IOS.SiriShortcuts.Count" units="shortcuts"
    expires_after="2021-10-04">
  <owner>gujen@google.com</owner>
  <owner>sebsg@chromium.org</owner>
  <summary>
    Counts the number of Chrome Siri Shortcuts that the user has created in the
    Siri Shortcuts app. This is recorded once during startup. The histogram caps
    at 20 shortcuts, which is an arbitrary but reasonable limit. Note that
    shortcuts that have multiple actions are not counted if at least one action
    isn't a Chrome-provided one. For example, a shortcut that opens URLs in
    Chrome and then opens URLs in another app won't be counted. As such, this
    metric undercounts the true number of Chrome shortcuts. This is a
    restriction of the native Shortcuts API.
  </summary>
</histogram>

<histogram name="IOS.Snapshots.CacheSize" units="KB" expires_after="2021-09-12">
  <owner>ajuma@chromium.org</owner>
  <owner>edchin@chromium.org</owner>
  <summary>
    The overall size of snapshots cache. Recorded when new snapshot is cached.
  </summary>
</histogram>

<histogram name="IOS.Snapshots.ImageSize" units="KB" expires_after="2021-09-12">
  <owner>ajuma@chromium.org</owner>
  <owner>edchin@chromium.org</owner>
  <summary>
    The size of a single snapshot image. Recorded when new snapshot is taken and
    RecordSnapshotSize flag is enabled.
  </summary>
</histogram>

<histogram name="IOS.Snapshots.PDFSize" units="KB" expires_after="2021-09-12">
  <owner>ajuma@chromium.org</owner>
  <owner>edchin@chromium.org</owner>
  <summary>
    The size of a single snapshot PDF. Recorded when new snapshot is taken and
    RecordSnapshotSize flag is enabled.
  </summary>
</histogram>

<histogram name="IOS.Spotlight.Action" enum="IOSSpotlightAction"
    expires_after="2021-09-12">
  <owner>olivierrobin@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>The Spotlight Action pressed by the user.</summary>
</histogram>

<histogram name="IOS.Spotlight.Availability" enum="IOSSpotlightAvailability"
    expires_after="2021-09-12">
  <owner>rohitrao@chromium.org</owner>
  <owner>olivierrobin@chromium.org</owner>
  <summary>
    Tracks the availability of the Spotlight indexation on the device. It is
    logged once at each cold start. Note: Spotlight may be available on the
    device but disabled by the user.
  </summary>
</histogram>

<histogram name="IOS.Spotlight.BookmarksIndexingDuration" units="ms"
    expires_after="2021-09-12">
  <owner>olivierrobin@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>Time spent in Spotlight initial indexation of bookmarks.</summary>
</histogram>

<histogram name="IOS.Spotlight.BookmarksInitialIndexSize" units="units"
    expires_after="2021-09-12">
  <owner>olivierrobin@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>Number of bookmarks indexed during initial indexation.</summary>
</histogram>

<histogram name="IOS.Spotlight.Origin" enum="IOSSpotlightOrigin"
    expires_after="2021-10-10">
  <owner>olivierrobin@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>
    This event is recorded each time a Chrome Spotlight entry is selected by the
    user. The enumeration indicates the nature of the Spotlight entry.
  </summary>
</histogram>

<histogram name="IOS.StoreKit.ITunesURLsHandlingResult"
    enum="IOSITunesURLsStoreKitHandlingResult" expires_after="2021-06-23">
  <owner>mrefaat@chromium.org</owner>
  <owner>rohitrao@chromium.org</owner>
  <summary>
    The result of StoreKit handling for a specific iTunes URL. Not Handled will
    be logged when the LinksHandler didn't handle a specific URL on purpose (not
    supported), and Failure will be logged when a URL that should have been
    handled wasn't handled.
  </summary>
</histogram>

<histogram name="IOS.StoreKitLoadedSuccessfully" enum="BooleanSuccess"
    expires_after="2021-08-01">
  <owner>mrefaat@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    Whether the StoreKit loaded the required iTunes product successfully or not.
  </summary>
</histogram>

<histogram name="IOS.TabSwitcher.PageChangeInteraction"
    enum="IOSTabSwitcherPageChangeInteraction" expires_after="M99">
  <owner>marq@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    The UI interaction by which the user changed the visible page in the tab
    switcher.
  </summary>
</histogram>

<histogram name="IOS.TabSwitcher.TimeSpent" units="ms"
    expires_after="2022-01-28">
  <owner>mrefaat@chromium.org</owner>
  <owner>marq@chromium.org</owner>
  <summary>
    The time the Tab switcher is displayed to the user. This histogram will
    always be recorded once the user exit the tab switcher.
  </summary>
</histogram>

<histogram name="IOS.Web.URLDidChangeToEmptyURL" enum="BooleanHit"
    expires_after="2021-11-30">
  <owner>gambard@chromium.org</owner>
  <owner>justincohen@chromium.org</owner>
  <summary>
    A boolean that is used to indicate that the URL property of the WKWebView
    has changed to a nil or empty URL. Recorded on the KVO of the URL of the
    WKWebView.
  </summary>
</histogram>

<histogram name="IOS.WidgetKit.Action" enum="IOSWidgetKitAction"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>muradyan@google.com</owner>
  <summary>
    Measures UI interactions in WidgetKit extension. Recorded after a user taps
    in a widget and Chrome is openned.
  </summary>
</histogram>

<histogram name="IOS.WidgetKit.{Status}" enum="IOSWidgetKitExtensionKind"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>muradyan@chromium.org</owner>
  <summary>
    Indicates the {Status} of an iOS 14 widget. Logged when the app goes to
    foreground. &quot;Current&quot; widgets are logged everytime widgets are
    detected, &quot;Install&quot; and &quot;Uninstall&quot; are logged only when
    changes are detected. It is important to consider the bias created towards
    users that foreground the app more often when doing analysis. This can be
    accounted by filtering per unique users when looking at the metric.
  </summary>
  <token key="Status">
    <variant name="Current" summary="presence"/>
    <variant name="Install" summary="installation"/>
    <variant name="Uninstall" summary="removal"/>
  </token>
</histogram>

<histogram name="IOS.WKWebViewClobberedHistory" enum="Boolean"
    expires_after="2021-09-24">
  <owner>ajuma@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    Measures the number of main frame navigations in slim navigation manager
    that are affected by a WKWebView bug that corrupts back/forward history
    (http://crbug.com/887497). This is recorded during WKWebView's
    decidePolicyForNavigationAction callback. True means the bug is triggered.
    False means the bug is not triggered.
  </summary>
</histogram>

<histogram name="IOS.WKWebViewFinishBeforeCommit" enum="Boolean"
    expires_after="M77">
  <owner>gambard@chromium.org</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    WKWebView should notify navigation commit before navigation finish, but
    exceptions have been observed. This histogram counts the frequency of this
    invariant violation at the time when a new navigation is finished. True
    means navigation finish callback happened before navigation commit.
  </summary>
</histogram>

<histogram name="IOS.WKWebViewLinkPreview" enum="IOSWKWebViewLinkPreviewAction"
    expires_after="M73">
  <obsolete>
    Deprecated 12/2020 as it is no longer used for analysis.
  </obsolete>
  <owner>kkhorimoto@chromium.org</owner>
  <owner>pkl@chromium.org</owner>
  <summary>
    Records the user actions related to the WKWebView 3D touch link preview API.
  </summary>
</histogram>

<histogram name="ManualFallback.PresentedOptions.AllPasswords"
    units="Credentials" expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    [iOS Only] Tracks the number of credentials presented to the user in the
    &quot;Use other password...&quot; view in Manual Fallback. This is logged
    everytime the user opens this view.
  </summary>
</histogram>

<histogram name="ManualFallback.PresentedOptions.CreditCards" units="Cards"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    [iOS Only] Tracks the number of cards presented to the user in Manual
    Fallback. This is logged everytime the user opens this view.
  </summary>
</histogram>

<histogram name="ManualFallback.PresentedOptions.Passwords" units="Credentials"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    [iOS Only] Tracks the number of credentials presented to the user in the
    Passwords Manual Fallback view. This is logged everytime the user opens this
    view.
  </summary>
</histogram>

<histogram name="ManualFallback.PresentedOptions.Profiles" units="Profiles"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    [iOS Only] Tracks the number of profiles presented to the user in Manual
    Fallback. This is logged everytime the user opens this view.
  </summary>
</histogram>

<histogram name="ManualFallback.VisibleSuggestions.OpenCreditCards"
    units="Suggestions" expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    [iOS Only] Tracks the number of autofill suggestions present when the user
    taps on the credit card button in manual fallback.
  </summary>
</histogram>

<histogram name="ManualFallback.VisibleSuggestions.OpenPasswords"
    units="Suggestions" expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    [iOS Only] Tracks the number of password suggestions present when the user
    taps on the password button in manual fallback.
  </summary>
</histogram>

<histogram name="ManualFallback.VisibleSuggestions.OpenProfiles"
    units="Suggestions" expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>gambard@chromium.org</owner>
  <summary>
    [iOS Only] Tracks the number of autofill suggestions present when the user
    taps on the profiles (address) button in manual fallback.
  </summary>
</histogram>

<histogram name="UserInterfaceStyle.CurrentlyUsed" enum="IOSUserInterfaceStyle"
    expires_after="2021-12-11">
  <owner>javierrobles@chromium.org</owner>
  <owner>rkgibson@google.com</owner>
  <owner>bling-team@google.com</owner>
  <summary>
    [iOS Only] Used on iOS 13+ to report the usage of Light and Dark mode. This
    is logged at startup and on each user interface style change. Can be caused
    by the system automatic switch or by the user manually changing the style.
  </summary>
</histogram>

</histograms>

</histogram-configuration>