metrics/histograms/histograms_xml/subresource/histograms.xml

<!--
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<!--
This file is used to generate a comprehensive list of Subresource 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
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reviews. Googlers can read more about this at go/gwsq-gerrit.
-->

<histogram-configuration>

<histograms>

<histogram name="SubresourceFilter.Actions2" enum="SubresourceFilterActions2"
    expires_after="2021-08-22">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Counts of various UI and user action events related to the
    SubresourceFilter. This will be triggered when portions of the UI are shown
    or interacted with.
  </summary>
</histogram>

<histogram name="SubresourceFilter.CnameAlias.Browser.HadAliases"
    units="BooleanHadAliases" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records whether or not a given NavigationRequest has a nonempty vector of
    CNAME aliases. Only recorded if
    features::kSendCnameAliasesToSubresourceFilterFromBrowser is enabled.
    Recorded in a method called in the SubframeNavigationFilteringThrottle's
    destructor.
  </summary>
</histogram>

<histogram name="SubresourceFilter.CnameAlias.Browser.InvalidCount"
    units="count" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Counts the number of invalid CNAME aliases seen for a NavigationRequest by
    the SubframeNavigationFilteringThrottle. Only recorded if
    features::kSendCnameAliasesToSubresourceFilterFromBrowser is enabled and the
    request has a nonempty vector of CNAME aliases. Recorded in a method called
    in the SubframeNavigationFilteringThrottle's destructor.
  </summary>
</histogram>

<histogram name="SubresourceFilter.CnameAlias.Browser.ListLength"
    units="length" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records the lengths of each CNAME aliases vector passed to the
    SubframeNavigationFilteringThrottle, not including empty alias vectors. Only
    recorded if features::kSendCnameAliasesToSubresourceFilterFromBrowser is
    enabled and the request has a nonempty vector of CNAME aliases. Recorded in
    a method called in the SubframeNavigationFilteringThrottle's destructor.
  </summary>
</histogram>

<histogram name="SubresourceFilter.CnameAlias.Browser.RedundantCount"
    units="count" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Counts the number of CNAME aliases seen by the
    SubframeNavigationFilteringThrottle that match the host of the requested
    URL. Only recorded if
    features::kSendCnameAliasesToSubresourceFilterFromBrowser is enabled and the
    request has a nonempty vector of CNAME aliases. Recorded in a method called
    in the SubframeNavigationFilteringThrottle's destructor.
  </summary>
</histogram>

<histogram
    name="SubresourceFilter.CnameAlias.Browser.WasAdTaggedBasedOnAliasCount"
    units="count" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Counts the number of CNAME aliases seen for a given NavigationRequest for
    which LoadPolicy::kWouldDisallow was returned due to an alias match. Only
    recorded if features::kSendCnameAliasesToSubresourceFilterFromBrowser is
    enabled and the request has a nonempty vector of CNAME aliases. Recorded in
    a method called in the SubframeNavigationFilteringThrottle's destructor.
  </summary>
</histogram>

<histogram
    name="SubresourceFilter.CnameAlias.Browser.WasBlockedBasedOnAliasCount"
    units="count" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Counts the number of CNAME aliases seen for a given NavigationRequest for
    which LoadPolicy::kDisallow was returned due to an alias match. Only
    recorded if features::kSendCnameAliasesToSubresourceFilterFromBrowser is
    enabled and the request has a nonempty vector of CNAME aliases. Recorded in
    a method called in the SubframeNavigationFilteringThrottle's destructor.
  </summary>
</histogram>

<histogram name="SubresourceFilter.CnameAlias.Renderer.HadAliases"
    units="BooleanHadAliases" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records whether or not a given ResourceLoader's ResourceRequest has a
    nonempty vector of CNAME aliases. Only recorded if
    features::kSendCnameAliasesToSubresourceFilterFromRenderer is enabled.
    Recorded in a method called by
    blink::ResourceLoader::DidReceiveResponseInternal.
  </summary>
</histogram>

<histogram name="SubresourceFilter.CnameAlias.Renderer.InvalidCount"
    units="count" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Counts the number of invalid CNAME aliases encountered by the
    ResourceLoader, as these are not sent to the SubResourceFilter. Only
    recorded if features::kSendCnameAliasesToSubresourceFilterFromRenderer is
    enabled and the request has a nonempty vector of CNAME aliases. Recorded in
    a method called by blink::ResourceLoader::DidReceiveResponseInternal.
  </summary>
</histogram>

<histogram name="SubresourceFilter.CnameAlias.Renderer.ListLength"
    units="length" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records the length of the CNAME aliases vector passed to the ResourceLoader,
    not including empty alias vectors. Only recorded if
    features::kSendCnameAliasesToSubresourceFilterFromRenderer is enabled and
    the request has a nonempty vector of CNAME aliases. Recorded in a method
    called by blink::ResourceLoader::DidReceiveResponseInternal.
  </summary>
</histogram>

<histogram name="SubresourceFilter.CnameAlias.Renderer.RedundantCount"
    units="count" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Counts the number of CNAME aliases encountered by the ResourceLoader that
    match the host of the requested URL (as well as the number of any that the
    match the host of the original URL in the case of redirects), as these
    aliases are not sent to the SubResourceFilter. Only recorded if
    features::kSendCnameAliasesToSubresourceFilterFromRenderer is enabled and
    the request has a nonempty vector of CNAME aliases. Recorded in a method
    called by blink::ResourceLoader::DidReceiveResponseInternal.
  </summary>
</histogram>

<histogram name="SubresourceFilter.CnameAlias.Renderer.WasAdTaggedBasedOnAlias"
    units="BooleanTagged" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records whether or not a given ResourceLoader's ResourceRequest has CNAME
    alias for which the returned LoadPolicy was LoadPolicy::kWouldDisallow. Only
    recorded if features::kSendCnameAliasesToSubresourceFilterFromRenderer is
    enabled and the request has a nonempty vector of CNAME aliases. Recorded in
    a method called by blink::ResourceLoader::DidReceiveResponseInternal.
  </summary>
</histogram>

<histogram name="SubresourceFilter.CnameAlias.Renderer.WasBlockedBasedOnAlias"
    units="BooleanBlocked" expires_after="2021-06-18">
  <owner>cammie@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records whether or not a given ResourceLoader's ResourceRequest has CNAME
    alias for which the returned LoadPolicy was LoadPolicy::kDisallow. Only
    recorded if features::kSendCnameAliasesToSubresourceFilterFromRenderer is
    enabled and the request has a nonempty vector of CNAME aliases. Recorded in
    a method called by the destructor of blink::ResourceLoader.
  </summary>
</histogram>

<histogram name="SubresourceFilter.DocumentLoad.Activation.CPUDuration"
    units="microseconds" expires_after="M77">
  <owner>pkalinnikov@chromium.org</owner>
  <summary>
    Records how much thread CPU time it takes to decide whether subresource
    filtering should be activated for a main frame or subframe.

    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="SubresourceFilter.DocumentLoad.Activation.WallDuration"
    units="microseconds" expires_after="M77">
  <owner>pkalinnikov@chromium.org</owner>
  <summary>
    Records how long it takes to decide whether subresource filtering should be
    activated for a main frame or subframe.

    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="SubresourceFilter.DocumentLoad.ActivationState"
    enum="SubresourceFilterActivationState" expires_after="2020-10-04">
  <owner>engedy@chromium.org</owner>
  <summary>
    Whenever a document load is committed in a main frame or subframe, records
    whether subresource filtering should be activated for that load.
  </summary>
</histogram>

<histogram name="SubresourceFilter.DocumentLoad.RulesetIsAvailable"
    enum="BooleanAvailable" expires_after="M77">
  <owner>engedy@chromium.org</owner>
  <summary>
    Whenever a document load is committed in a main frame or subframe and
    subresource filtering should be activated, records whether the filtering
    rules are available.
  </summary>
</histogram>

<histogram name="SubresourceFilter.DocumentLoad.SubframeFilteringDelay.Allowed"
    units="microseconds" expires_after="2021-08-09">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records the total time a subframe navigation was delayed while calculating
    whether it should be disallowed or not. Logged for all navigations that were
    allowed.

    This metric uses UMA_HISTOGRAM_CUSTOM_MICROSECONDS_TIMES to acccount for
    clients with low-resolution clocks.
  </summary>
</histogram>

<histogram
    name="SubresourceFilter.DocumentLoad.SubframeFilteringDelay.Disallowed2"
    units="microseconds" expires_after="M92">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records the total time a subframe navigation was delayed while calculating
    whether it should be disallowed or not. Logged for all navigations with the
    disallowed load policy.

    This metric uses UMA_HISTOGRAM_CUSTOM_MICROSECONDS_TIMES to acccount for
    clients with low-resolution clocks.
  </summary>
</histogram>

<histogram
    name="SubresourceFilter.DocumentLoad.SubframeFilteringDelay.WouldDisallow"
    units="microseconds" expires_after="M92">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records the total time a subframe navigation was delayed while calculating
    whether it should be disallowed or not. Logged for all navigations with the
    would_disallow load policy.

    This metric uses UMA_HISTOGRAM_CUSTOM_MICROSECONDS_TIMES to acccount for
    clients with low-resolution clocks.
  </summary>
</histogram>

<histogram name="SubresourceFilter.IndexRuleset.CPUDuration" units="ms"
    expires_after="2020-02-02">
  <owner>pkalinnikov@chromium.org</owner>
  <summary>
    The total CPU time it took to parse and index all rules. Does not include
    time when the indexing thread was not doing actual work, e.g. waiting for
    I/O or being descheduled. Recorded every time the RulesetService kicks off a
    ruleset indexing process.
  </summary>
</histogram>

<histogram name="SubresourceFilter.IndexRuleset.NumUnsupportedRules"
    units="rules" expires_after="M90">
  <owner>jkarlin@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    The number of rules that could be not be successfully indexed and therefore
    have been ignored. Recorded every time the RulesetService kicks off a
    ruleset indexing process and it reaches the point where rules are getting
    indexed. This is logged when a new ruleset is indexed for the first time on
    Chrome start.
  </summary>
</histogram>

<histogram name="SubresourceFilter.IndexRuleset.Verify.Status"
    enum="SubresourceFilterVerifyStatus" expires_after="2021-10-10">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    The result of the IndexRulesetMatcher Verify method. Either pass if both the
    checksum and verifier succeeded, or a value indicating which combination of
    them failed. Note that a zero checksum indicates that the checksum has not
    yet been stored during indexing (for rulesets indexed prior to the
    checksumming code). This is logged when the indexed ruleset is loaded on
    Chrome start.
  </summary>
</histogram>

<histogram name="SubresourceFilter.IndexRuleset.Verify2.WallDuration"
    units="ms" expires_after="M92">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    The total time it took to verify the indexed ruleset in the browser process.
    Logged every time verification occurs, which usually occurs when the first
    page with activation is navigated to. This is logged when the indexed
    ruleset is loaded on Chrome start.
  </summary>
</histogram>

<histogram name="SubresourceFilter.IndexRuleset.WallDuration" units="ms"
    expires_after="M92">
  <owner>jkarlin@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    The total time it took to read and index all rules. Includes I/O time for
    reading the unindexed rules, but not for writing the indexed ruleset.
    Recorded every time the RulesetService kicks off a ruleset indexing process.
  </summary>
</histogram>

<histogram
    name="SubresourceFilter.MainFrameLoad.RulesetIsAvailableAnyActivationLevel"
    enum="BooleanAvailable" expires_after="2021-08-09">
  <owner>alexmt@chromium.org</owner>
  <owner>jkarlin@chromium.org</owner>
  <summary>
    Whenever a document load is committed in the main frame, records whether the
    filtering rules are available. This is independent of whether or not
    subresource filtering should be activated.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.Activation.CPUDuration"
    units="microseconds" expires_after="2018-08-30">
  <obsolete>
    Removed in 10/2020 after being expired two years. Presumably not used.
  </obsolete>
  <owner>csharrison@chromium.org</owner>
  <summary>
    Records how much thread CPU time it takes to decide whether subresource
    filtering should be activated for a main frame.

    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="SubresourceFilter.PageLoad.Activation.RedirectPosition2.Enforcement"
    enum="RedirectPosition" expires_after="M78">
  <obsolete>
    Removed in 10/2020 after being expired over a year. Presumably not used.
  </obsolete>
  <owner>ericrobinson@chromium.org</owner>
  <owner>csharrison@chromium.org</owner>
  <summary>
    For pages that match a given subresource_filter activation list, records the
    position in the redirect chain of the latest non-NONE list.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.Activation.WallDuration"
    units="microseconds" expires_after="2018-08-30">
  <obsolete>
    Removed in 10/2020 after being expired two years. Presumably not used.
  </obsolete>
  <owner>csharrison@chromium.org</owner>
  <summary>
    Records how long it takes to decide whether subresource filtering should be
    activated for a main frame.

    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="SubresourceFilter.PageLoad.ActivationDecision"
    enum="SubresourceFilterActivationDecision" expires_after="2021-08-22">
  <owner>jkarlin@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records the policy decision to activate subresource filtering for a page
    load. 'Activated' indicates that subresource filtering was activated. All
    other reasons indicate that subresource filtering was not activated.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.ActivationList"
    enum="ActivationList" expires_after="2021-09-12">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    The ActivationList or NONE that the main frame navigation matched with.
    Recorded at WillProcessResponse time for a main frame navigation.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.ActivationState"
    enum="SubresourceFilterActivationState" expires_after="2021-09-12">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Whenever a document load is committed in a main frame, records whether
    subresource filtering should be activated for that load. Also records the
    same for the initial document load, even if it was not committed.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.ActivationState.DidInherit"
    enum="SubresourceFilterActivationState" expires_after="2021-11-02">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Whenever a document load is committed in a main frame that inherits from its
    same-origin opener, records whether subresource filtering should be
    activated for that load. Also records the same for the initial document load
    (if it inherits its activation) even if it was not committed.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.AdsInterventionTriggered"
    enum="AdsViolations" expires_after="M90">
  <owner>yaoxia@google.com</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records that an ads violation has been triggered on a page load. Logged at
    the time the ads violation is detected.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.NumSubresourceLoads.Disallowed"
    units="resource loads" expires_after="2021-08-09">
  <owner>jkarlin@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Whenever a page load is finished with subresource filtering activated,
    records the total number of subresource loads that have been disallowed.
    This only differs from `MatchedRules` when filtering is performed in dry-run
    mode.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.NumSubresourceLoads.Evaluated"
    units="resource loads" expires_after="M92">
  <owner>jkarlin@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Whenever a page load is finished with subresource filtering activated,
    records the total number of subresource loads that have been evaluated. This
    only differs from 'Total' when some of subdocuments is subject to a
    deactivating rule with DOCUMENT activation type.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.NumSubresourceLoads.MatchedRules"
    units="resource loads" expires_after="2021-10-10">
  <owner>jkarlin@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Whenever a page load is finished with subresource filtering activated,
    records the total number of subresource loads that have matched filtering
    rules. This only differs from `Disallowed` when filtering is performed in
    dry-run mode.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.NumSubresourceLoads.Total"
    units="resource loads" expires_after="M92">
  <owner>jkarlin@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Whenever a page load is finished with subresource filtering activated,
    records the total number of subresource loads that have gone through the
    subresource filtering pipeline.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.SafeBrowsingDelay" units="ms"
    expires_after="M92">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    The navigation delay imposed by the subresource filter on a given navigation
    due to Safe Browsing checks.

    This metric expired after M83 and was renewed in M88, so it has incomplete
    data between M84 and M87 inclusively.
  </summary>
</histogram>

<histogram
    name="SubresourceFilter.PageLoad.SubresourceEvaluation.TotalCPUDuration"
    units="microseconds" expires_after="2020-01-26">
  <owner>pkalinnikov@chromium.org</owner>
  <summary>
    Whenever a page load is finished with subresource filtering activated,
    records the total thread CPU time spent on evaluating subresource requests,
    aggregated across all frames.

    Note: this histogram is emitted for all clients, both ones which have
    high-resolution timer available and those which don't.
  </summary>
</histogram>

<histogram
    name="SubresourceFilter.PageLoad.SubresourceEvaluation.TotalWallDuration"
    units="microseconds" expires_after="M78">
  <owner>pkalinnikov@chromium.org</owner>
  <summary>
    Whenever a page load is finished with subresource filtering activated,
    records the total real time spent on evaluating subresource requests,
    aggregated across all frames. This includes the time spent on waiting or
    being descheduled.

    Note: this histogram is emitted for all clients, both ones which have
    high-resolution timer available and those which don't.
  </summary>
</histogram>

<histogram name="SubresourceFilter.PageLoad.TimeSinceLastActiveAdsIntervention"
    units="hours" expires_after="M90">
  <owner>yaoxia@google.com</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records the time since the last ads intervention when loading a page that
    has previously triggered an ads intervention. This is limited by the maximum
    expiry time of intervention data, 7 days. Recorded at the time page
    activation is computed during page load when a previous intervention was
    previously recorded and has not expired from the intervention data.
  </summary>
</histogram>

<histogram name="SubresourceFilter.RulesetVerificationStatus"
    enum="RulesetVerificationStatus" expires_after="M77">
  <owner>yaoxia@chromium.org</owner>
  <summary>
    Records the ruleset verification status at some point in a browsing session.
    If AdTagging is disabled, this happens when the user first visits a site
    that is failing the Better Ads Standard, and gets ads blocked on that site;
    if AdTagging is enabled, this happens immediately on startup. Note that this
    is recorded only once per browsing session (the lifetime of the browser
    process).
  </summary>
</histogram>

<histogram name="SubresourceFilter.SafeBrowsing.TotalCheckTime" units="ms"
    expires_after="2021-10-10">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    The time an individual Safe Browsing URL check took before finishing,
    including posting tasks to and from the IO thread. Measured on the UI thread
    on navigation.

    This metric expired after M83 and was renewed in M88, so it has incomplete
    data between M84 and M87 inclusively.
  </summary>
</histogram>

<histogram name="SubresourceFilter.SubresourceLoad.Evaluation.CPUDuration"
    units="microseconds" expires_after="2020-01-26">
  <owner>pkalinnikov@chromium.org</owner>
  <summary>
    Whenever a subresource of a document is evaluated against the ruleset,
    records the thread CPU time spent on calculating whether it should be
    allowed to load.

    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="SubresourceFilter.SubresourceLoad.Evaluation.WallDuration"
    units="microseconds" expires_after="M85">
  <owner>pkalinnikov@chromium.org</owner>
  <summary>
    Whenever a subresource of a document is evaluated against the ruleset,
    records how much time was spent on calculating whether it should be allowed
    to load.

    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="SubresourceFilter.WriteRuleset.ReplaceFileError"
    enum="PlatformFileError" expires_after="M90">
  <owner>jkarlin@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Records the exact error whenever writing a ruleset fails at the step where
    the ruleset would be moved from the scratch directory to its final location.
    Recorded every time the RulesetService kicks off a ruleset indexing process.
  </summary>
</histogram>

<histogram name="SubresourceFilter.WriteRuleset.Result"
    enum="SubresourceFilterWriteRulesetResult" expires_after="M92">
  <owner>alexmt@chromium.org</owner>
  <owner>chrome-ads-histograms@google.com</owner>
  <summary>
    Whether indexing a version of the ruleset and writing it to disk succeeded,
    or failed at a particular step. Recorded every time the RulesetService kicks
    off a ruleset indexing process.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.Blink.Ineligibility"
    enum="BlinkSubresourceRedirectIneligibility" expires_after="2021-10-10">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the different reasons subresource redirect was disabled by Blink.
    Recorded for each subresource that was disabled by Blink.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.BypassDuration" units="ms"
    expires_after="M92">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the duration that the subresource redirect feature was stopped due
    to fetch failure. When such a redirected fetch times out or fails with 503
    (loadshed failure), subresource redirect is disabled for subsequent
    pageloads for a random duration or duration mentioned in the Retry-After
    response header. Recorded for each fetch failure.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.CompressionAttempt.ResponseCode"
    enum="HttpResponseCode" expires_after="2021-08-22">
  <owner>robertogden@chromium.org</owner>
  <owner>tbansal@chromium.org</owner>
  <summary>
    The server response code of an attempt to compress an image subresource. The
    initial redirect to the compression server will always be logged as a
    HTTP_TEMPORARY_REDIRECT, in addition to logging the return code from the
    compression server.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.CompressionAttempt.ServerResponded"
    enum="Boolean" expires_after="M92">
  <owner>robertogden@chromium.org</owner>
  <owner>tbansal@chromium.org</owner>
  <summary>
    Whether or not the request to the compression server succeeded at the
    network layer. Records true if there was no error at the network layer,
    otherwise false.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.CompressionFetchTimeout" enum="Boolean"
    expires_after="M92">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Recorded whenever the subresource redirect times out, and leads to a random
    bypass of 1-5 minutes.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.DidCompress.BytesSaved" units="bytes"
    expires_after="2021-10-10">
  <owner>robertogden@chromium.org</owner>
  <owner>tbansal@chromium.org</owner>
  <summary>
    The bytes of data saved from the SubresourceRedirect. Recorded every time a
    SubresourceRedirect returns with a 200 HTTP response code.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.DidCompress.CompressionPercent" units="%"
    expires_after="2021-10-10">
  <owner>robertogden@chromium.org</owner>
  <owner>tbansal@chromium.org</owner>
  <summary>
    The percent of data saved from the SubresourceRedirect. Recorded every time
    a SubresourceRedirect returns with a 200 HTTP response code.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.ImageCompressionNotificationInfoBar"
    enum="HttpsImageCompressionInfoBarAction" expires_after="2021-08-09">
  <owner>rajendrant@chromium.org</owner>
  <owner>src/components/data_reduction_proxy/OWNERS</owner>
  <summary>
    Records the user interaction with the HTTPS Image compression notification
    InfoBar. Recorded when the one-time InfoBar is shown.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.LitePagesService.BypassResult"
    enum="Boolean" expires_after="M92">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records whether the LitePages service fetches were bypassed or not. Recorded
    once per LitePages server accesss. Currently LitePages service is used for
    fetching compressed images and robots.txt rules.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.LoginRobotsDeciderAgent.RedirectResult"
    enum="SubresourceRedirectRedirectResult" expires_after="M92">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the different results possible for subresource redirection, such as
    redirectable or different reasons of ineligibility. Recorded once for each
    image request.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.PageLoad.BypassResult" enum="Boolean"
    expires_after="M92">
  <obsolete>
    Replaced by SubresourceRedirect.LitePagesService.BypassResult on 11/2020
  </obsolete>
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records whether the subresource redirect was bypassed or not for a pageload.
    Recorded once per pageload.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.RobotRulesDecider.ApplyDuration"
    units="ms" expires_after="M92">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the duration that the robots rules decider took to apply the rules.
    Recorded once for each image fetch. There could be multiple robots rules for
    an image origin, and the total duration needed to match with all the rules
    and make the final Allow/Disallow decision is recorded here.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.RobotRulesDecider.Count" units="count"
    expires_after="M92">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the total number of robots rules received in the decider. Recorded
    whenever robots rules decider object receives successfully parsable robots
    rules.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.RobotRulesDecider.ReceiveResult"
    enum="SubresourceRedirectRobotsRulesReceiveResult" expires_after="M92">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the final result of retrieving robots.txt rules. Recorded once per
    robots rules decider object, which is roughly the number of unique image
    origins in the page.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.RobotsRules.Browser.InMemoryCacheHit"
    units="BooleanCacheHit" expires_after="M92">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records how often the origin robots rules were found in the in-memory
    browser cache. Recorded for every robots rules request from renderer that is
    eligible to check the in-memory cache.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.RobotsRulesFetcher.CacheHit" units="ms"
    expires_after="M92">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records whether LitePages robots rules was fetched from Chrome network
    cache. Recorded for every fetch.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.RobotsRulesFetcher.NetErrorCode"
    enum="NetErrorCodes" expires_after="M92">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Net error codes for the LitePages robots rules fetcher. Recorded on every
    fetch after completion or failure.
  </summary>
</histogram>

<histogram name="SubresourceRedirect.RobotsRulesFetcher.ResponseCode"
    units="HttpResponseCode" expires_after="M92">
  <owner>rajendrant@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    HTTP response code for the LitePages robots rules fetcher. Recorded on every
    fetch after completion or failure.
  </summary>
</histogram>

</histograms>

</histogram-configuration>