tools/metrics/histograms/metadata/optimization/histograms.xml

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

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

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

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

<histogram-configuration>

<histograms>

<variants name="AnnotationType">
  <variant name="ContentVisibility" summary="Content Visibility"/>
  <variant name="PageEntities" summary="Page Entities"/>
  <variant name="PageTopics" summary="Page Topics"/>
  <variant name="Unknown" summary="Unknown"/>
</variants>

<variants name="OptimizationTarget">
  <variant name="ClientSidePhishing" summary="Client Side Phishing"/>
  <variant name="ContextualPageActionPriceTracking"
      summary="Contextual Page Action: Show price tracking"/>
  <variant name="GeolocationPermissions" summary="Geolocation permissions"/>
  <variant name="LanguageDetection" summary="Language detection"/>
  <variant name="ModelValidation" summary="Model validation triggered via CLI"/>
  <variant name="NewTabPageHistoryClustersModuleRanking"
      summary="New Tab Page History Clusters Module Ranking"/>
  <variant name="NotificationPermissions" summary="Notification permissions"/>
  <variant name="OmniboxOnDeviceTailSuggest"
      summary="Omnibox on device tail suggest"/>
  <variant name="OmniboxUrlScoring" summary="Omnibox Url scoring"/>
  <variant name="PageEntities" summary="Page entities"/>
  <variant name="PageTopics" summary="Page topics"/>
  <variant name="PageTopicsV2" summary="Page topics v2"/>
  <variant name="PageVisibility" summary="Page visibility"/>
  <variant name="PainfulPageLoad" summary="Painful page load"/>
  <variant name="SegmentationAdaptiveToolbar"
      summary="Segmentation: Adaptive toolbar button"/>
  <variant name="SegmentationChromeLowUserEngagement"
      summary="Segmentation: Low user engagement with Chrome"/>
  <variant name="SegmentationChromeStartAndroid"
      summary="Chrome Start Android"/>
  <variant name="SegmentationChromeStartAndroidV2"
      summary="Chrome Start Android V2"/>
  <variant name="SegmentationDeviceSwitcher"
      summary="Segmentation: Device switcher"/>
  <variant name="SegmentationDummyFeature" summary="Dummy feature"/>
  <variant name="SegmentationFeedUser"
      summary="Segmentation: Feed usage in Chrome"/>
  <variant name="SegmentationNewTab" summary="Segmentation: New tab page user"/>
  <variant name="SegmentationQueryTiles" summary="Query tiles"/>
  <variant name="SegmentationSearchUser" summary="Segmentation: Search user"/>
  <variant name="SegmentationShare" summary="Segmentation: Share user"/>
  <variant name="SegmentationShoppingUser"
      summary="Segmentation: Shopping user"/>
  <variant name="SegmentationTabletProductivityUser"
      summary="Segmentation: Tablet Productivity user"/>
  <variant name="SegmentationVoice" summary="Segmentation: Voice user"/>
  <variant name="TextClassifier" summary="Smart text selection"/>
  <variant name="WebAppInstallationPromo"
      summary="PWA: Show web app installation promotion"/>
</variants>

<variants name="OptimizationType">
  <variant name="AboutThisSite"
      summary="Provides 'About this site' data about the site being visited"/>
  <variant name="AutofillSamplingRate"
      summary="This optimization provides information about a sampling rate
               of Autofill UKM metrics per origin based on origin popularity."/>
  <variant name="BloomFilterValidation"
      summary="Validates bloom filer allowlist/blocklist based hints"/>
  <variant name="CompressPublicImages" summary="Compresses public images"/>
  <variant name="DeferAllScript" summary="Defers execution of script"/>
  <variant name="FastHostHints"
      summary="Provides information about hosts that historically provide a
               fast and responsive user experience"/>
  <variant name="HistoryClusters"
      summary="This optimization provides information for whether a page
               should be included in a history cluster."/>
  <variant name="IBANAutofillBlocked"
      summary="This optimization provides information for whether a page
               should be blocked for IBAN autofill feature."/>
  <variant name="LinkPerformance"
      summary="Provides aggregated performance information for links on the
               page"/>
  <variant name="LitePage"
      summary="HTTP server preview (served from the Data Reduction Proxy)"/>
  <variant name="LiteVideo"
      summary="Provides information on how to throttle media requests to
               reduce the adaptive bit rates of media streams."/>
  <variant name="LoadingPredictor"
      summary="Provides information about subresources predicted to be on the
               page"/>
  <variant name="LoginDetection"
      summary="Provides information about hosts that are identified as
               commonly logged-in"/>
  <variant name="MerchantTrustSignals"
      summary="Provides trust data related to the merchant."/>
  <variant name="MerchantTrustSignalsV2"
      summary="Provides trust data related to the merchant -- version 2."/>
  <variant name="MetadataFetchValidation"
      summary="Validates metadata fetch on navigation"/>
  <variant name="PageEntities"
      summary="Provides the entities that are present on the page"/>
  <variant name="PerformanceHints"
      summary="Provides aggregated performance information about the page"/>
  <variant name="PriceTracking"
      summary="Returns price related data for shopping websites"/>
  <variant name="SalientImage"
      summary="Provides information about images for a URL."/>
  <variant name="ShoppingPagePredictor"
      summary="Determines if a page is shopping related or not"/>
  <variant name="ThankCreatorEligible"
      summary="This optimization provides information for whether a page is
               eligible for the 'Thank Creator' feature."/>
  <variant name="VcnMerchantOptOutVisa"
      summary="This optimization provides information about whether a
               merchant is opted-out of Visa virtual cards for a URL."/>
</variants>

<variants name="PageContentAnnotationsStorageType">
  <variant name="ModelAnnotations" summary="Model Annotations"/>
  <variant name="RelatedSearches" summary="Related Searches"/>
  <variant name="RemoteMetadata" summary="Remote Metadata"/>
  <variant name="SalientImageMetadata" summary="Salient Image Metadata"/>
  <variant name="SearchMetadata" summary="Search Metadata"/>
  <variant name="Unknown" summary="Unknown"/>
</variants>

<variants name="PageTextDumpEvent">
  <variant name="FinishedLoad" summary="finished load"/>
  <variant name="FirstLayout" summary="first layout"/>
</variants>

<variants name="RequestContext">
  <variant name="BatchUpdateActiveTabs"
      summary="Batch update of hints for active tabs"/>
  <variant name="BatchUpdateGoogleSRP"
      summary="Batch update of hints for result links off the Google SRP"/>
  <variant name="BatchUpdateModels" summary="Batch update of models"/>
  <variant name="Bookmarks" summary="Batch update of hints for bookmarks"/>
  <variant name="Journeys" summary="Journeys surface"/>
  <variant name="NewTabPage" summary="New tab page"/>
  <variant name="PageNavigation" summary="Page navigation"/>
</variants>

<histogram name="OptimizationGuide.ApplyDecision.{OptimizationType}"
    enum="OptimizationGuideOptimizationTypeDecision" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    The decision made for whether {OptimizationType} can be applied on the page
    load.
  </summary>
  <token key="OptimizationType" variants="OptimizationType"/>
</histogram>

<histogram name="OptimizationGuide.ApplyDecisionAsync.{OptimizationType}"
    enum="OptimizationGuideOptimizationTypeDecision" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the decision made for whether {OptimizationType} can be applied on a
    page load when all information for that page load has been sufficiently
    gathered. This will be recorded once per callback registered, so if two
    callbacks were registered for {OptimizationType} on the same page load, this
    will be recorded twice for that case.
  </summary>
  <token key="OptimizationType" variants="OptimizationType"/>
</histogram>

<histogram name="OptimizationGuide.ClearFetchedHints.StoreAvailable"
    enum="BooleanAvailable" expires_after="2023-06-18">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records whether the optimization guide store was available when fetched
    hints are cleared from the store after browser history is cleared.
  </summary>
</histogram>

<histogram name="OptimizationGuide.ClearHostModelFeatures.StoreAvailable"
    enum="BooleanAvailable" expires_after="2022-01-28">
  <obsolete>
    Deprecated as of 2022-01-28.
  </obsolete>
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records whether the optimization guide store was available when host model
    features are cleared from the store after browser history is cleared.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.EntityAnnotatorNativeLibrary.InitiatedSuccessfully"
    enum="BooleanSuccess" expires_after="2023-10-08">
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether the entity annotator native library was initiated
    successfully if an attempt to load it was made.
  </summary>
</histogram>

<histogram name="OptimizationGuide.HintCache.HintType.Loaded"
    enum="HintCacheStoreEntryType" expires_after="2023-06-25">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the store entry type of a hint when it is loaded from the hint cache
    store.
  </summary>
</histogram>

<histogram name="OptimizationGuide.HintCacheLevelDBStore.LoadMetadataResult"
    enum="OptimizationGuideHintCacheLevelDBStoreLoadMetadataResult"
    expires_after="2023-06-18">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the result of loading the metadata while initializing the
    HintCacheLevelDBStore.
  </summary>
</histogram>

<histogram name="OptimizationGuide.HintCacheLevelDBStore.Status"
    enum="OptimizationGuideHintCacheLevelDBStoreStatus"
    expires_after="2023-10-22">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records each status change within the HintCacheLevelDBStore.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.HintsFetcher.GetHintsRequest.ActiveRequestCanceled.{RequestContext}"
    units="counts" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records when an in-flight hints request for {RequestContext} was canceled
    before it finished.
  </summary>
  <token key="RequestContext" variants="RequestContext"/>
</histogram>

<histogram
    name="OptimizationGuide.HintsFetcher.GetHintsRequest.DroppedHosts.{RequestContext}"
    units="counts" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the number of hosts that were dropped for a request made with
    {RequestContext}, if the number of hosts dropped is non-zero. Will record at
    most once per fetch.
  </summary>
  <token key="RequestContext" variants="RequestContext"/>
</histogram>

<histogram
    name="OptimizationGuide.HintsFetcher.GetHintsRequest.DroppedUrls.{RequestContext}"
    units="counts" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the number of URLs that were dropped for a request made with
    {RequestContext}, if the number of URLs dropped is non-zero. Will record at
    most once per fetch.
  </summary>
  <token key="RequestContext" variants="RequestContext"/>
</histogram>

<histogram
    name="OptimizationGuide.HintsFetcher.GetHintsRequest.FetchLatency.{RequestContext}"
    units="ms" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    The duration of a request to fetch hints from the remote Optimization Guide
    Service starts until it completes. Recorded every time hints are fetched and
    parsed successfully.
  </summary>
  <token key="RequestContext" variants="RequestContext"/>
</histogram>

<histogram name="OptimizationGuide.HintsFetcher.GetHintsRequest.HintCount"
    units="units" expires_after="2023-09-10">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the number of hints received from the remote Optimization Guide
    Service for every successful HintsFetch request.
  </summary>
</histogram>

<histogram name="OptimizationGuide.HintsFetcher.GetHintsRequest.HostCount"
    units="total host count" expires_after="2023-07-09">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the number of hosts selected for sending a hint request. This will
    be captured when any hint request is initiated.
  </summary>
</histogram>

<histogram name="OptimizationGuide.HintsFetcher.GetHintsRequest.NetErrorCode"
    enum="NetErrorCodes" expires_after="2023-10-08">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Net error codes for HintsFetch requests to the Optimization Guide Service on
    success and failure.
  </summary>
</histogram>

<histogram name="OptimizationGuide.HintsFetcher.GetHintsRequest.Status"
    enum="HttpResponseCode" expires_after="2023-10-08">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    For each HintsFetch request to the Optimization Guide Service, log the HTTP
    response code on success and failure.
  </summary>
</histogram>

<histogram name="OptimizationGuide.HintsFetcher.GetHintsRequest.UrlCount"
    units="total url count" expires_after="2023-09-10">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the number of URLs selected for sending a hint request. This will be
    captured when any hint request is initiated.
  </summary>
</histogram>

<histogram name="OptimizationGuide.HintsFetcher.RequestStatus.{RequestContext}"
    enum="OptimizationGuideHintsFetcherRequestStatus" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    The status of making a request using {RequestContext} of the
    OptmizationGuide HintsFetcher. This includes whether a network request was
    actually sent or not.
  </summary>
  <token key="RequestContext" variants="RequestContext"/>
</histogram>

<histogram name="OptimizationGuide.HintsManager.ActiveTabUrlsToFetchFor"
    units="counts" expires_after="2023-10-15">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    The number of active tab URLs that did not have a hint on device, and thus,
    required a fetch for a new hint. Recorded when a fetch is initiated to the
    remote Optimization Guide Service for active tabs, roughly once an hour but
    configurable via experiment params.
  </summary>
</histogram>

<histogram name="OptimizationGuide.HintsManager.ConcurrentBatchUpdateFetches"
    units="counts" expires_after="2023-10-15">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    The number of active batch update hints fetches initiated by the hints
    manager. Recorded when a fetch is initiated to the remote Optimization Guide
    Service for a batch update context (i.e. on SRP, other UI surfaces, etc.).
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.HintsManager.ConcurrentPageNavigationFetches"
    units="counts" expires_after="2023-09-03">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    The number of active hints fetches initiated by the hints manager. Recorded
    when a fetch is initiated to the remote Optimization Guide Service at
    navigation start.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.HintsManager.PageNavigationHintsReturnedBeforeDataFlushed"
    enum="BooleanStored" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records whether a page navigation hints fetch returned before navigation
    data used to record additional page load metrics is flushed. Recorded only
    for navigations that have a hints fetch initiated for it.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.HintsManager.RaceNavigationFetchAttemptStatus"
    enum="OptimizationGuideRaceNavigationFetchAttemptStatus"
    expires_after="2023-09-10">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Status of a fetch attempt being raced against the current navigation start
    and whether it includes hosts and urls. Recorded on navigation start
    (including client redirects) by the hints manager.
  </summary>
</histogram>

<histogram name="OptimizationGuide.IsPredictionModelValid.{OptimizationTarget}"
    enum="BooleanValid" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records whether the prediction model being constructed for
    {OptimizationTarget} is valid or not. Recorded when prediction models are
    loaded into memory by the prediction manager.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram name="OptimizationGuide.MetadataFetchValidation.Result"
    enum="Boolean" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether the metadata fetch validation received the hints correctly.
    Recorded on iOS when the mainframe navigation commits.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.ModelExecutor.DidTimeout.{OptimizationTarget}"
    enum="Boolean" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether the model execution for {OptimizationTarget} was cancelled
    due to running past the configured timeout.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.ModelExecutor.ExecutionLatency.{OptimizationTarget}"
    units="ms" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the time duration it took execute the model for
    {OptimizationTarget}. Recorded once per model execution for
    {OptimizationTarget}.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.ModelExecutor.ExecutionStatus.{OptimizationTarget}"
    enum="OptimizationGuideExecutionStatus" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the result of attempting to execute a {OptimizationTarget} model,
    including loading the file from disk. Recorded once per model execution
    attempt for {OptimizationTarget}.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.ModelExecutor.ExecutionThreadTime.{OptimizationTarget}"
    units="ms" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the time duration it took to execute the model for
    {OptimizationTarget}. Recorded once per model execution for
    {OptimizationTarget}. This is effectively the same as
    `OptimizationGuide.ModelExecutor.ExecutionLatency.{OptimizationTarget}` but
    this is recorded using `base::ElapsedThreadTimer` instead.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.ModelExecutor.ModelAvailableToLoad.{OptimizationTarget}"
    enum="BooleanAvailable" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether the model file for {OptimizationTarget} is available on disk
    at the time when it needs to be loaded into memory for a requested
    execution. Recorded once per model load attempt for {OptimizationTarget}.
    Note that callers may separately check whether a model is available before
    calling the code path where this histogram is recorded. If this histogram
    has 100% of samples in the true bucket, make sure to double-check that there
    isn't a separate histogram specific to the model.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.ModelExecutor.ModelLoadingDuration2.{OptimizationTarget}"
    units="ms" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the time duration it took to load a model file successfully for
    {OptimizationTarget}. Recorded once per model load attempt for
    {OptimizationTarget}.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.ModelExecutor.TaskExecutionLatency.{OptimizationTarget}"
    units="ms" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the execution latency for the {OptimizationTarget} model run by the
    model executor from when the task is posted from execution complete.
    Recorded once per {OptimizationTarget} model execution attempt.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.ModelExecutor.TaskSchedulingLatency.{OptimizationTarget}"
    units="ms" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the duration a {OptimizationTarget} model execution request spent
    waiting for the background task queue to run the task. Recorded once per
    {OptimizationTarget} model execution attempt.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.ModelExecutor.TimeSincePreviousRun.{OptimizationTarget}"
    units="ms" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the time duration between runs of the model for
    {OptimizationTarget}. Recorded once for every model run after the first.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram name="OptimizationGuide.ModelFilesVerified.{OptimizationTarget}"
    enum="BooleanValid" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether all model files existed on disk when the model was requested
    to be loaded for {OptimizationTarget}. The model file itself and any
    additional files must be present on disk for this check to report success.
    Recorded once per attempted model load, which happens when a feature is
    registered with the Optimization Guide.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.ModelHandler.HandlerCreated.{OptimizationTarget}"
    enum="BooleanCreated" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records that the model handler has been created for {OptimizationTarget}.
    Recorded once for each session (profile start) that the model handler is
    created for {OptimizationTarget}.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.ModelHandler.HandlerCreatedToModelAvailable.{OptimizationTarget}"
    units="ms" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the time duration between the handler getting created to the model
    being available for {OptimizationTarget}. Recorded once for each session
    (profile start) that the model handler is created for {OptimizationTarget}.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram name="OptimizationGuide.OptimizationFilterStatus.{OptimizationType}"
    enum="OptimizationGuideOptimizationFilterStatus" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Status of processing OptimizationFilter configuration for
    {OptimizationType}. Recorded when the OptimizationGuideService receives a
    notification to process hints.
  </summary>
  <token key="OptimizationType" variants="OptimizationType"/>
</histogram>

<histogram name="OptimizationGuide.OptimizationHintsComponent.MajorVersion"
    units="major version number" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the major version of the Optimization Hints component that was
    pushed to the client. This will be recorded at startup and when a new
    component is received.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotations.AnnotateVisitResultCached"
    enum="BooleanCacheHit" expires_after="2023-09-10">
  <owner>mcrouse@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether the requested annotation for a visit was provided by the
    in-memory cache or required them to be determined by executing the models.
    Recorded once for every requested visit annotation.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotations.BatchRequestedSize.{AnnotationType}"
    units="counts" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the size of a {AnnotationType} BatchAnnotate request in how many
    string inputs were given. Recorded once for every call to BatchAnnotate.
  </summary>
  <token key="AnnotationType" variants="AnnotationType"/>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotations.BatchSuccess.{AnnotationType}"
    enum="BooleanSuccess" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether any input to a {AnnotationType} BatchAnnotate request was
    executed successfully. Recorded once for every completed callback for
    BatchAnnotate.
  </summary>
  <token key="AnnotationType" variants="AnnotationType"/>
</histogram>

<histogram name="OptimizationGuide.PageContentAnnotations.EntityCollection_50"
    enum="OptimizationGuidePageEntityCollection" expires_after="2023-09-17">
  <owner>tbansal@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Emits all collections associated high weight entities (with score equal or
    higher than 50 on a scale of 0 to 100) associated with a page visit.

    Note that these are emitted when the user browses to a webpage. When that
    happens, multiple collections may be emitted per webpage. Only the
    collections associated with high weight entities are recorded.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotations.JobExecutionTime.{AnnotationType}"
    units="ms" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the total execution time of a {AnnotationType} BatchAnnotate
    request. Recorded once for every completed callback for BatchAnnotate.
  </summary>
  <token key="AnnotationType" variants="AnnotationType"/>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotations.JobScheduleTime.{AnnotationType}"
    units="ms" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the time a {AnnotationType} BatchAnnotate request was waiting in the
    queue before execution started. Recorded once for every completed callback
    for BatchAnnotate.
  </summary>
  <token key="AnnotationType" variants="AnnotationType"/>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotations.SalientImageAvailability"
    enum="OptimizationGuideSalientImageAvailability" expires_after="2023-09-10">
  <owner>tbansal@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>Records the availability of salient images on page load.</summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotations.TemplateURLServiceLoadedAtNavigationFinish"
    enum="BooleanLoaded" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether the TemplateURLService was available and loaded at
    navigation finish. Recorded once per page load.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotationsService.ContentAnnotated"
    enum="BooleanAnnotated" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records whether the page content was annotated successfully, if submitted
    for annotation. This will approximately be once a page load after the page
    load has finished loading.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotationsService.ContentAnnotationsStorageMinMagnitudeForVisitNotFound"
    units="ms" expires_after="2023-06-04">
  <obsolete>
    Obsolete as of 04/2023.
  </obsolete>
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the magnitude of the visit times between the visit that data is
    supposed to be stored for and the closest visit for the same URL if the
    specific visit, as identified by URL and time, was not found when storing
    the data for a particular visit. This may be recorded multiple times per
    page load as different pieces of data are stored for a visit separately
    (i.e. related searches, model annotations, etc.).
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotationsService.ContentAnnotationsStorageMinMagnitudeForVisitNotFound.{PageContentAnnotationsStorageType}"
    units="ms" expires_after="M117">
  <obsolete>
    Obsolete as of 04/2023.
  </obsolete>
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the magnitude of the visit times between the visit that
    {PageContentAnnotationsStorageType} is supposed to be stored for and the
    closest visit for the same URL if the specific visit, as identified by URL
    and time, was not found when storing the {PageContentAnnotationsStorageType}
    for a particular visit. This will be recorded at most once per page load.
  </summary>
  <token key="PageContentAnnotationsStorageType"
      variants="PageContentAnnotationsStorageType"/>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotationsService.ContentAnnotationsStorageStatus"
    enum="OptimizationGuidePageContentAnnotationsStorageStatus"
    expires_after="2023-10-22">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the status of whether the content annotations were stored in History
    Service when the necessary data has been collected successfully. This will
    be recorded multiple times per page load, for both the related searches as
    well as the model annotations once the page has finished loading.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotationsService.ContentAnnotationsStorageStatus.{PageContentAnnotationsStorageType}"
    enum="OptimizationGuidePageContentAnnotationsStorageStatus"
    expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records the status of whether the {PageContentAnnotationsStorageType} were
    stored in History Service when the data has been collected successfully.
    This will record at most once per page load.
  </summary>
  <token key="PageContentAnnotationsStorageType"
      variants="PageContentAnnotationsStorageType"/>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotationsService.ModelAvailable"
    enum="BooleanAvailable" expires_after="2022-10-30">
  <obsolete>
    Removed in M103.
  </obsolete>
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Whether the page topics model was available to execute when requested.
    Recorded once per execution attempt. Note that this histogram supersedes
    OptimizationGuide.ModelExecutor.ModelAvailableToLoad.PageTopics.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotationsService.ModelExecutionLatency.PageEntities"
    units="ms" expires_after="2023-10-08">
  <owner>mcrouse@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the model execution latency for the PageEntities model only just the
    annotation request. This does not include any thread hop or queuing delay.
    Recorded once per model execution attempt.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotationsService.ModelThreadExecutionLatency.PageEntities"
    units="ms" expires_after="2023-10-08">
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the model execution latency for the PageEntities model. This does
    not include any thread hop or queuing delay. Recorded once per model
    execution attempt. This is effectively the same as
    OptimizationGuide.PageContentAnnotationsService.ModelExecutionLatency.PageEntities
    but uses `base::ElapsedThreadTimer` to calculate the timing.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotationsService.PageEntitiesExecutionLatency"
    units="ms" expires_after="2022-10-30">
  <obsolete>
    Removed in M103.
  </obsolete>
  <owner>mcrouse@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the execution latency for the PageEntities model from when the model
    manager requests the execution to completion and only if a result is
    returned. This includes thread queuing and hopping time. Recorded once per
    model execution attempt.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotationsService.RelatedSearchesExtracted"
    enum="BooleanAnnotated" expires_after="2023-10-08">
  <owner>mahmadi@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records whether related searches were successfully extracted from Google
    SRP, if requested. This will be recorded approximately once per page load
    after the page has finished loading.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageContentAnnotationsService.VisibilityScoreOfGoogleSRP"
    units="score" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the visibility score of Google Search Result Pages when the page's
    annotation is complete.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageEntitiesModelExecutor.CreatedSuccessfully"
    enum="BooleanSuccess" expires_after="2023-03-26">
  <obsolete>
    Renamed to OptimizationGuide.PageEntitiesModelHandler.CreatedSuccessfully in
    M110.
  </obsolete>
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether the page entities model executor was created successfully
    from a model file. Recorded each time it was attempted, which can be
    multiple times a session if a model update was received during the session.
  </summary>
</histogram>

<histogram name="OptimizationGuide.PageEntitiesModelExecutor.CreationStatus"
    enum="OptimizationGuideEntityAnnotatorCreationStatus"
    expires_after="2023-03-26">
  <obsolete>
    Renamed to OptimizationGuide.PageEntitiesModelHandler.CreationStatus in
    M110.
  </obsolete>
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the status for the page entities model executor's creation. Recorded
    each time it was attempted, which can be multiple times a session if a model
    update was received during the session.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageEntitiesModelHandler.CreatedSuccessfully"
    enum="BooleanSuccess" expires_after="2023-08-27">
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether the page entities model handler was created successfully
    from a model file. Recorded each time it was attempted, which can be
    multiple times a session if a model update was received during the session.
  </summary>
</histogram>

<histogram name="OptimizationGuide.PageEntitiesModelHandler.CreationStatus"
    enum="OptimizationGuideEntityAnnotatorCreationStatus"
    expires_after="2023-08-27">
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the status for the page entities model handler's creation. Recorded
    each time it was attempted, which can be multiple times a session if a model
    update was received during the session.
  </summary>
</histogram>

<histogram name="OptimizationGuide.PageTextDump.AbandonedRequests"
    units="count" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    The number of text dump requests that were sent to the renderer and did not
    get a response after a grace period following DidFinishLoad, thus were
    abandoned. This may be recorded multiple times per pageload.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageTextDump.FrameDumpLength.{PageTextDumpEvent}"
    units="bytes" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    The length, in bytes, of every completed frame dump for the
    {PageTextDumpEvent} event. Note that these values are capped at runtime to
    an experimentally controlled value.
  </summary>
  <token key="PageTextDumpEvent" variants="PageTextDumpEvent"/>
</histogram>

<histogram
    name="OptimizationGuide.PageTextDump.OutstandingRequests.DidFinishLoad"
    units="count" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    The number of outstanding page text dump requests at DidFinishLoad.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PageTextDump.TimeUntilFrameDisconnected.{PageTextDumpEvent}"
    units="ms" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    The duration it took for a frame dump request, for the {PageTextDumpEvent}
    event, from being sent until being canceled. Recorded every time a request
    is canceled. This normally occurs because the mojo pipe disconnected.
  </summary>
  <token key="PageTextDumpEvent" variants="PageTextDumpEvent"/>
</histogram>

<histogram
    name="OptimizationGuide.PageTextDump.TimeUntilFrameDumpCompleted.{PageTextDumpEvent}"
    units="ms" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    The duration it took for a frame dump request for the {PageTextDumpEvent}
    event, to complete successfully. Recorded every time a request completes
    successfully.
  </summary>
  <token key="PageTextDumpEvent" variants="PageTextDumpEvent"/>
</histogram>

<histogram name="OptimizationGuide.PageTopicsOverrideList.FileLoadResult"
    enum="OptimizationGuidePageTopicsOverrideListFileLoadResult"
    expires_after="2023-10-15">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    The result of a single attempt to load the override list from disk, and
    parse it into a native object. Recorded once for every attempted load. Note
    that if an attempt fails it will not be re-attempted for the same file until
    the next browsing session, but a successful load will be recorded one or
    more times during a browsing session.
  </summary>
</histogram>

<histogram name="OptimizationGuide.PageTopicsOverrideList.GotFile"
    enum="Boolean" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Whether the override list file was packaged with the model, recorded each
    time a model file becomes available.
  </summary>
</histogram>

<histogram name="OptimizationGuide.PageTopicsOverrideList.UsedOverride"
    enum="Boolean" expires_after="2023-10-15">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    When the override list is loaded, whether it contained the given input.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PredictionManager.DownloadServiceAvailabilityBlockedFetch"
    enum="BooleanBlocked" expires_after="2023-10-01">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records whether the Download Service was unavailable and blocked a fetch
    that would have happened otherwise. Only recorded if model downloads are
    enabled for the session.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PredictionManager.FirstModelFetchSinceServiceInit"
    units="ms" expires_after="M117">
  <owner>rajendrant@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the time duration it took for the first model fetch to start from
    the time the optimization guide service was initialized. Recorded once at
    startup when the first model fetch happens.
  </summary>
</histogram>

<histogram name="OptimizationGuide.PredictionManager.HostModelFeaturesMapSize"
    units="total host count" expires_after="2022-01-28">
  <obsolete>
    Deprecated as of 2022-01-28.
  </obsolete>
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the number of host model features loaded into the map used by the
    PredictionManager. This is recorded when the host model features are loaded
    from the store.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PredictionManager.IsDownloadUrlValid.{OptimizationTarget}"
    enum="BooleanValid" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records whether the download URL for {OptimizationTarget} received from the
    remote Optimization Guide server is valid.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionManager.ModelAvailableAtRegistration.{OptimizationTarget}"
    enum="BooleanAvailable" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records whether the model was in the local store for {OptimizationTarget}
    when the observer for {OptimizationTarget} was registered with the
    prediction manager. Recorded at most once per session (profile start) when
    {OptimizationTarget} is registered.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionManager.ModelDeliveryEvents.{OptimizationTarget}"
    enum="OptimizationGuideModelDeliveryEvent" expires_after="M117">
  <owner>rajendrant@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the different events of prediction model delivery lifecycle for
    {OptimizationTarget}, such as fetching model metadata, downloading model
    file, verification, unzipping, etc. Recorded whenever lifecycle state
    changes.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionManager.ModelTypeChanged.{OptimizationTarget}"
    enum="BooleanChanged" expires_after="2022-03-07">
  <obsolete>
    Deprecated as of 2022-03-07.
  </obsolete>
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records whether the model type changed for {OptimizationTarget} from model
    proto to model file, or vice versa when the in-memory model for an
    optimization target has been loaded.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionManager.RegistrationTimeSinceServiceInit.{OptimizationTarget}"
    units="ms" expires_after="M117">
  <owner>rajendrant@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the time duration it took for the feature to register with the
    optimization guide for {OptimizationTarget} from the time the optimization
    guide service was initialized. Recorded once when the feature registers with
    the service.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelDownloadManager.DownloadStartLatency.{OptimizationTarget}"
    units="ms" expires_after="M117">
  <owner>rajendrant@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the time duration it took for the model download to be started by
    the download service for {OptimizationTarget} from the time it was requested
    by the optimization guide. Recorded once per model download when model
    download starts successfully.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelDownloadManager.DownloadStatus"
    enum="OptimizationGuidePredictionModelDownloadStatus"
    expires_after="2023-10-15">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    The status of verifying and processing model downloads. Recorded once per
    file that was successfully downloaded via the Download Service.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelDownloadManager.DownloadSucceeded"
    enum="BooleanSuccess" expires_after="2023-10-15">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Records whether the Download Service notified whether a model download has
    succeeded or failed.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelDownloadManager.ReplaceFileError.{OptimizationTarget}"
    enum="PlatformFileError" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the exact error whenever writing a model file fails at the step
    where the model is moved from the scratch directory to its final location.
    Recorded every time a {OptimizationTarget} model file is downloaded and
    being processed for storage.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelDownloadManager.State.{OptimizationTarget}"
    enum="OptimizationGuidePredictionModelDownloadState" expires_after="M117">
  <owner>rajendrant@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    The state of a model download. Recorded multiple times per model file
    download, as the state is changed.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram name="OptimizationGuide.PredictionModelExpired.{OptimizationTarget}"
    enum="BooleanExpired" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether a prediction model for an OptimizationTarget expired if it
    was not updated or used within the configured expiration time, but can
    change subject to Finch or server configuration. Recorded once per browser
    startup.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelExpiredVersion.{OptimizationTarget}"
    units="version number" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the version of a prediction model for an OptimizationTarget that
    expired if it was not updated or used within the configured expiration time,
    but can change subject to Finch or server configuration. Recorded once per
    browser startup.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelFetcher.GetModelsResponse.NetErrorCode"
    enum="NetErrorCodes" expires_after="2023-10-22">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Net error codes for GetModelsRequest to the Optimization Guide Service on
    success and failure. Recorded once per GetModelsRequest where the model was
    fetched for. It is not advisable to sum up the counts across
    OptimizationTargets as the GetModelsRequests bundle requests for various
    OptimizationTargets into single request to the server.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelFetcher.GetModelsResponse.NetErrorCode.{OptimizationTarget}"
    enum="NetErrorCodes" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Net error codes for GetModelsRequest to the Optimization Guide Service on
    success and failure for {OptimizationTarget}. Recorded once per
    GetModelsRequest where the model for {OptimizationTarget} was fetched for.
    It is not advisable to sum up the counts across OptimizationTargets as the
    GetModelsRequests bundle requests for various OptimizationTargets into
    single request to the server.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelFetcher.GetModelsResponse.Status"
    enum="HttpResponseCode" expires_after="2023-10-22">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    For each GetModelsRequest to the Optimization Guide Service, log the HTTP
    response code on success and failure. Recorded once per GetModelsRequest
    where the model was fetched for. It is not advisable to sum up the counts
    across OptimizationTargets as the GetModelsRequests bundle requests for
    various OptimizationTargets into single request to the server.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelFetcher.GetModelsResponse.Status.{OptimizationTarget}"
    enum="HttpResponseCode" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    For each GetModelsRequest to the Optimization Guide Service for
    {OptimizationTarget}, log the HTTP response code on success and failure.
    Recorded once per GetModelsRequest where the model for {OptimizationTarget}
    was fetched for. It is not advisable to sum up the counts across
    OptimizationTargets as the GetModelsRequests bundle requests for various
    OptimizationTargets into single request to the server.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelLoadedVersion.{OptimizationTarget}"
    units="version number" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the version of the prediction model that was loaded from the store
    and used until updated by a fetch. Recorded only if the loaded model was
    valid.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelStore.HostModelFeaturesLoadMetadataResult"
    enum="BooleanLoaded" expires_after="2022-01-28">
  <obsolete>
    Deprecated as of 2022-01-28.
  </obsolete>
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the result of loading the host model features metadata while
    initializing the OptimizationGuideStore.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelStore.ModelCount.{OptimizationTarget}"
    units="counts" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>rajendrant@chromium.org</owner>
  <summary>
    The total number of model directories in the prediction model store for
    {OptimizationTarget}. Recorded once at startup.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram name="OptimizationGuide.PredictionModelStore.ModelRemovalReason"
    enum="OptimizationGuidePredictionModelStoreModelRemovalReason"
    expires_after="2023-10-15">
  <owner>rajendrant@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the reason the prediction model was removed from the model store.
    Recorded when the model is removed.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelStore.TotalDirectorySize.{OptimizationTarget}"
    units="MB" expires_after="M117">
  <owner>sophiechang@chromium.org</owner>
  <owner>rajendrant@chromium.org</owner>
  <summary>
    The total disk usage of the prediction model store attributed to
    {OptimizationTarget}. Recorded once at startup.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelUpdateVersion.{OptimizationTarget}"
    units="version number" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the version of the prediction model that was fetched as an update.
    Recorded only if a model returned was valid and is available for use.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram
    name="OptimizationGuide.PredictionModelValidationLatency.{OptimizationTarget}"
    units="ms" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Records the duration of construction and validation of a prediction model
    when the prediction manager loads it into memory for a given optimization
    target. Recorded only if the model is valid and successfully loaded into
    memory for use.
  </summary>
  <token key="OptimizationTarget" variants="OptimizationTarget"/>
</histogram>

<histogram name="OptimizationGuide.ProcessHintsResult"
    enum="OptimizationGuideProcessHintsResult" expires_after="2023-08-27">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Whether processing the hints succeeded or failed at a particular step.
    Recorded when the OptimizationGuideService receives a notification to
    process hints.
  </summary>
</histogram>

<histogram name="OptimizationGuide.ProcessingComponentAtShutdown"
    enum="BooleanYesNo" expires_after="M117">
  <owner>mcrouse@chromium.org</owner>
  <owner>sophiechang@chromium.org</owner>
  <summary>
    Whether the Optimization Hints component was being processed when the hints
    manager is told to shutdown.
  </summary>
</histogram>

<histogram name="OptimizationGuide.PushNotifications.CachedNotificationCount"
    units="count" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    The number of cached push notifications that were pulled from the Android
    cache after the native persistent store became fully initialized. Recorded
    once per native startup in cases where the cache did not overflow.
  </summary>
</histogram>

<histogram
    name="OptimizationGuide.PushNotifications.CachedNotificationsHandledSuccessfully"
    enum="BooleanSuccess" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Whether the push notification cache was handled successfully and was able to
    be cleared out. Recorded once per each attempt at handling one cache shard.
  </summary>
</histogram>

<histogram name="OptimizationGuide.PushNotifications.DidOverflow"
    enum="Boolean" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records whether the Android push notification cache overflowed and caused
    the whole store to be purged. Recorded once per native startup.
  </summary>
</histogram>

<histogram name="OptimizationGuide.PushNotifications.GotPushNotification"
    enum="Boolean" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>Records a true sample for every incoming push notification.</summary>
</histogram>

<histogram
    name="OptimizationGuide.PushNotifications.PushNotificationHandledSuccessfully"
    enum="BooleanSuccess" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Whether an incoming push notification was handled successfully. Recorded
    once for every such notification.
  </summary>
</histogram>

<histogram name="OptimizationGuide.PushNotifications.ReadCacheResult"
    enum="OptimizationGuideReadCacheResult" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the result of reading the cache of push notifications and parsing
    the encoded cache into protobufs. This is recorded once for every encoded
    protobuf that is read from cache.
  </summary>
</histogram>

<histogram name="OptimizationGuide.PushNotifications.ReceivedNotificationType"
    enum="OptimizationType" expires_after="M117">
  <owner>robertogden@chromium.org</owner>
  <owner>chrome-intelligence-core@google.com</owner>
  <summary>
    Records the OptimizationType of the push notification. Recorded when the
    notification is received and before the notification payload is delivered to
    feature handlers.
  </summary>
</histogram>

<histogram name="OptimizationGuide.RemoteFetchingEnabled" enum="BooleanEnabled"
    expires_after="2023-10-22">
  <owner>sophiechang@chromium.org</owner>
  <owner>mcrouse@chromium.org</owner>
  <summary>
    Whether the session is enabled for fetching information from the remote
    Optimization Guide Service. Recorded when the profile is initialized for the
    session if Optimization Hints are enabled and the profile is a non-incognito
    profile.
  </summary>
</histogram>

</histograms>

</histogram-configuration>