tools/metrics/histograms/metadata/web_core/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 WebCore 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
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have an OWNERS file. As a last resort you can send the CL to
chromium-metrics-reviews@google.com.
-->

<histogram-configuration>

<histograms>

<variants name="FindInPageRequestEndState">
  <variant name=".Aborted"
      summary="The request got aborted before it went through every text in
               the document."/>
  <variant name=".Finished"
      summary="The request finished going through every text in the document."/>
</variants>

<histogram name="WebCore.DistillabilityUs" units="microseconds"
    expires_after="2023-09-10">
  <owner>wychen@chromium.org</owner>
  <owner>gilmanmh@google.com</owner>
  <summary>
    The time spent on collecting the statistics of the document in the main
    frame. These statistics would be used as features to classify whether the
    page is suitable for DOM distiller.

    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="WebCore.Document.execCommand" enum="MappedEditingCommands"
    expires_after="2023-10-01">
  <owner>yosin@chromium.org</owner>
  <owner>kojii@chromium.org</owner>
  <summary>
    Counts the number of times each document.execCommand is executed. This
    doesn't count commands not supported by Blink.
  </summary>
</histogram>

<histogram name="WebCore.Editing.Commands" enum="MappedEditingCommands"
    expires_after="2023-07-31">
  <owner>yosin@chromium.org</owner>
  <owner>kojii@chromium.org</owner>
  <summary>
    Counts the number of times each Editor::Command::execute is called. This
    doesn't count commands not supported by Blink.
  </summary>
</histogram>

<histogram name="WebCore.FindInPage.DurationBetweenKeystrokes" units="ms"
    expires_after="2023-09-10">
  <owner>jarhar@chromium.org</owner>
  <owner>vmpstr@chromium.org</owner>
  <summary>
    Records the amount of time between keystrokes the user made while typing a
    search query into the find-in-page browser dialog. Reported on each Find
    request that extends the text of the previous request. This will be used in
    order to determine how long we should make the find-in-page scroll delay:
    http://crbug.com/1250158
  </summary>
</histogram>

<histogram
    name="WebCore.FindInPage.NumberOfTasksPerRequest{FindInPageRequestEndState}"
    units="tasks" expires_after="2021-04-04">
  <owner>rakina@chromium.org</owner>
  <owner>altimin@chromium.org</owner>
  <summary>
    Records the number of find-in-page tasks executed for a find-in-page
    request. Emitted when a find-in-page request is finished (it went through
    the whole document) or when it got aborted. {FindInPageRequestEndState}
  </summary>
  <token key="FindInPageRequestEndState" variants="FindInPageRequestEndState"/>
</histogram>

<histogram name="WebCore.FindInPage.RequestDuration{FindInPageRequestEndState}"
    units="ms" expires_after="2021-04-04">
  <owner>rakina@chromium.org</owner>
  <owner>altimin@chromium.org</owner>
  <summary>
    Records how long one find-in-page request (consisting multiple tasks) took
    from the request start until the last find-in-page task for the request
    finished. Emitted when a find-in-page request is finished (it went through
    the whole document) or when it got aborted. {FindInPageRequestEndState}
  </summary>
  <token key="FindInPageRequestEndState" variants="FindInPageRequestEndState"/>
</histogram>

<histogram name="WebCore.FindInPage.TaskDuration" units="ms"
    expires_after="2023-05-07">
  <owner>rakina@chromium.org</owner>
  <owner>altimin@chromium.org</owner>
  <summary>
    Records how long one find-in-page task took from invocation start to end.
    Emitted when a find-in-page task finished running.
  </summary>
</histogram>

<histogram
    name="WebCore.FindInPage.TotalTaskDuration{FindInPageRequestEndState}"
    units="ms" expires_after="2021-04-04">
  <owner>rakina@chromium.org</owner>
  <owner>altimin@chromium.org</owner>
  <summary>
    Records the total task duration of all of the find-in-page tasks for one
    find-in-page request. Nothe that this does not include the time spent in
    between tasks. Emitted when a find-in-page request is finished (it went
    through the whole document) or when it got aborted.
    {FindInPageRequestEndState}
  </summary>
  <token key="FindInPageRequestEndState" variants="FindInPageRequestEndState"/>
</histogram>

<histogram name="WebCore.Framebust.ClickThroughPosition"
    enum="ListItemPosition" expires_after="M110">
  <owner>csharrison@chromium.org</owner>
  <owner>japhet@chromium.org</owner>
  <summary>
    The position of the URL in the framebust UI list (desktop only) when it is
    clicked. Note that this UI surface is shared with the tab-under
    intervention, so elements in the list could come from either features. This
    metric will only be logged when a URL from the framebust (3p redirect)
    intervention is clicked.
  </summary>
</histogram>

<histogram name="WebCore.Framebust.InterventionOutcome"
    enum="FramebustInterventionOutcome" expires_after="M110">
  <owner>csharrison@chromium.org</owner>
  <owner>japhet@chromium.org</owner>
  <summary>
    The (android only) outcome of a particular framebust infobar. Recorded when
    the user either closes the infobar or declines the intervention by clicking
    the link.
  </summary>
</histogram>

<histogram name="WebCore.HTMLDocumentParser.PreloadScannerAppCacheDelayTime"
    units="microseconds" expires_after="2019-09-30">
  <owner>yoavweiss@chromium.org</owner>
  <owner>csharrison@chromium.org</owner>
  <summary>
    Time in which non-AppCache requests have been delayed after being discovered
    by the HTMLPreloadScanner, due to document element not being yet available,
    which is required for AppCache support. Recorded per document.
  </summary>
</histogram>

<histogram
    name="WebCore.HTMLDocumentParser.PreloadScannerAppCacheDelayTime.MainFrame"
    units="microseconds" expires_after="2019-09-30">
  <owner>yoavweiss@chromium.org</owner>
  <owner>csharrison@chromium.org</owner>
  <summary>
    Time in which non-AppCache requests have been delayed after being discovered
    by the HTMLPreloadScanner, due to document element not being yet available,
    which is required for AppCache support. Recorded per document, but applies
    only to main frames.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.BackingStore.Action" enum="IDBAction"
    expires_after="never">
<!-- expires-never: indexeddb heartbeat metric; used for chirp alerts (go/chrome-indexeddb-heartbeat) -->

  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Records actions that take place in IndexedDB. These stats are used for
    normalization in formulas. See go/chrome-indexeddb-heartbeat
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.BackingStore.ConsistencyError"
    enum="IDBLevelDBBackingStoreInternalErrorType" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Methods that encountered consistency errors. Such errors probably point to a
    bug in our code.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.BackingStore.DeleteDatabaseStatus"
    enum="LevelDBStatus" expires_after="never">
<!-- expires-never: indexeddb heartbeat metric; used for chirp alerts (go/chrome-indexeddb-heartbeat) -->

  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Records the result of trying to delete an IndexedDB database, per the user
    using the IDBFactory::DeleteDatabase API.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.BackingStore.OpenFirstTryResult"
    enum="LevelDBStatus" expires_after="never">
<!-- expires-never: indexeddb heartbeat metric; used for chirp alerts (go/chrome-indexeddb-heartbeat) -->

  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Records the result of the FIRST attempt at opening the backing store for
    IndexedDB (i.e. retries are ignored). This is recorded when an API call
    needs to open the backing store (if it isn't already opened). API calls that
    can open the backing store are: IDBFactory::Open, GetDatabaseNames,
    GetDatabaseInfo, and DeleteDatabase.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.BackingStore.OpenFirstTrySuccessTime"
    units="ms" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Records the time that it takes to open IndexedDB's backing store. This is
    only recorded if the backing store was opened successfully on the first
    attempt.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.BackingStore.OpenStatus"
    enum="IDBLevelDBBackingStoreOpenResult" expires_after="never">
<!-- expires-never: core storage metric; consumed in separate dashboard (go/chrome-storage-dashboard) -->

<!-- expires-never: indexeddb heartbeat metric; used for chirp alerts (go/chrome-indexeddb-heartbeat) -->

  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Count of the different success and failure modes when opening an IndexedDB
    backing store - clean open, successful open with recovery, failed recovery,
    etc. Includes all hosts.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.BackingStore.OpenStatus.Docs"
    enum="IDBLevelDBBackingStoreOpenResult" expires_after="never">
<!-- expires-never: core storage metric; consumed in separate dashboard (go/chrome-storage-dashboard) -->

  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Count of the different success and failure modes when opening an IndexedDB
    backing store - clean open, successful open with recovery, failed recovery,
    etc. Only for docs.google.com.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.BackingStore.OverlyLargeOriginLength"
    units="characters" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Length of leveldb directories that cause paths to not fit in the filesystem,
    either because the individual component is too long or the overall path is
    larger than MAX_PATH.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.BackingStore.ReadError"
    enum="IDBLevelDBBackingStoreInternalErrorType" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Methods that encountered leveldb errors while trying to read from disk.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.BackingStore.WriteError"
    enum="IDBLevelDBBackingStoreInternalErrorType" expires_after="2023-08-27">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Methods that encountered leveldb errors while trying to write to disk.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.Context.ForceCloseReason"
    enum="IDBContextForcedCloseReason" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>The reason that a forced-close of a backing store occurred.</summary>
</histogram>

<histogram name="WebCore.IndexedDB.ErrorDuringForceCloseAborts"
    enum="LevelDBStatus" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Recorded when there is an error during the force close of IndexedDB for an
    origin. A force close can be triggered either from DevTools, or when there
    is a disk error. Errors during force close are ignored, as the system is
    already being torn down. This metric is the only record of these errors
    happening.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.FoundBlobFileForValue" enum="Boolean"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Recorded when a blob is attempted to be read from an IndexedDB value. This
    is triggered for both implicit blob-wrapped large values and explicit blob
    values. Its value is false iff there was a file not found value when reading
    the file. This metric is to help track down the rate of missing files for
    http://crbug.com/1131151.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDB.CloseTime" units="ms"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The time that it takes to close IndexedDB's LevelDB backing store.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDB.OpenTime" units="ms"
    expires_after="2023-08-27">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The time that it takes to open IndexedDB's LevelDB backing store.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDB.WriteTime" units="ms"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The time that it takes to write data to an IndexedDB's LevelDB backing
    store.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBOpenErrors" enum="LevelDBErrorTypes"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Error classes returned by LevelDB when it failed to open a database.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBOpenErrors.BFE"
    enum="PlatformFileError" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Errors (base::File::Error) encountered by a single LevelDBEnv method when
    opening an IndexedDB instance.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBOpenErrors.Corruption"
    enum="LevelDBCorruptionTypes" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Types of corruption that LevelDB encounters when opening a database.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBOpenErrors.EnvMethod"
    enum="LevelDBIOErrorMethods" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    LevelDBEnv methods that generated IO errors when opening a database.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBReadErrors" enum="LevelDBErrorTypes"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Error classes returned by LevelDB when it failed to read a database.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBReadErrors.BFE"
    enum="PlatformFileError" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Errors (base::File::Error) encountered by a single LevelDBEnv method when
    reading from an IndexedDB instance.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBReadErrors.Corruption"
    enum="LevelDBCorruptionTypes" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Types of corruption that LevelDB encounters when reading a database.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBReadErrors.EnvMethod"
    enum="LevelDBIOErrorMethods" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    LevelDBEnv methods that generated IO errors when reading a database.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBWriteErrors" enum="LevelDBErrorTypes"
    expires_after="2023-08-27">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Error classes returned by LevelDB when it failed to write to a database.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBWriteErrors.BFE"
    enum="PlatformFileError" expires_after="2023-09-03">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Errors (base::File::Error) encountered by a single LevelDBEnv method when
    writing to an IndexedDB instance.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBWriteErrors.Corruption"
    enum="LevelDBCorruptionTypes" expires_after="2023-08-27">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Types of corruption returned by LevelDB when it failed to write to a
    database.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.LevelDBWriteErrors.EnvMethod"
    enum="LevelDBIOErrorMethods" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    LevelDBEnv methods that generated IO errors when writing to a database.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.OpenTime.Cold" units="ms"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Records the full time it takes to open a database that isn't open yet (so
    files are loaded from disk, metadata checked, etc). The measurement happens
    when a website calls &quot;indexedDB.open&quot;, and records the time it
    takes from when this method is called to when the onsuccess event (or
    onupgradeneeded event, in the case of a database upgrade) is dispatched. See
    WebCore.IndexedDB.OpenTime.Warm for the time it takes an already-loaded
    database to load.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.OpenTime.Warm" units="ms"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Records the full time it takes to open an already-open database. The
    measurement happens when a website calls &quot;indexedDB.open&quot;, and
    records the time it takes from when this method is called to when the
    onsuccess event (or onupgradeneeded event, in the case of a database
    upgrade) is dispatched. See WebCore.IndexedDB.OpenTime.Cold for the time it
    takes to open a database that is not open yet.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.PutBlobsCount" units="blobs"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The number of blobs being saved in an IndexedDB object store 'put'
    operation. Recorded for every 'put' operation.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.PutBlobsTotalSize" units="KB"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The total size of the blobs being saved in an IndexedDB object store 'put'
    operation. Recorded for every 'put' operation, except when there are no
    attached blobs or a blob has an unknown size.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.PutKeySize" units="KB"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The size of the IndexedDB key used in an IndexedDB object store 'put'
    operation. Recorded for every 'put' operation.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.PutValueSize2" units="KB"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The size of the IndexedDB value used in an IndexedDB object store 'put'
    operation. Recorded for every 'put' operation.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.TombstoneSweeper.DeletedTombstonesSize"
    units="bytes" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Records the total size of tombstones deleted by the IndexedDB Tombstone
    Sweeper. Recorded on the browser side (back end) when the sweeper has
    completed scanning and it is in the 'deletion' mode. See
    https://goo.gl/coKwA7.
  </summary>
</histogram>

<histogram
    name="WebCore.IndexedDB.TombstoneSweeper.DeletionCommitTime.Complete"
    units="ms" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Records the time it takes for the IndexedDB Tombstone Sweeper to commit
    tombstone deletions. Recorded on the browser side (back end) when the
    sweeper has completed a round of sweeping and, it's in 'deletion' mode, and
    it has tombstones to delete. See https://goo.gl/coKwA7.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.TombstoneSweeper.DeletionTotalTime.Complete"
    units="ms" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Records the time it takes for the IndexedDB Tombstone Sweeper to fully sweep
    the indexes. Recorded on the browser side (back end) when the sweeper has
    completed sweeping all indexes (so partial sweeps are not recorded) and it
    is in 'deletion' mode. See https://goo.gl/coKwA7.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.TombstoneSweeper.DeletionWriteError"
    enum="LevelDBStatus" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Records when an error occurs during deletion of index tombstones by the
    IndexedDB Tombstone Sweeper. Recorded on the browser side (back end) when
    the sweeper has completed a round of sweeping and, it's in 'deletion' mode,
    and it has tombstones to delete. See https://goo.gl/coKwA7.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.TombstoneSweeper.IndexScanPercent"
    units="%/5" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Recorded on the browser side (back end) when the IndexedDB Tombstone Sweeper
    has completed scanning. Records the percentage of the indexes the scanner
    fully scanned before it was stopped. To reduce the number of buckets, the
    recorded value is the percentage divided by 5. See https://goo.gl/coKwA7.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.TombstoneSweeper.NumDeletedTombstones"
    units="Index Tombstones" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Records the number of tombstones deleted by the IndexedDB Tombstone Sweeper.
    Recorded on the browser side (back end) when the sweeper has completed
    scanning and it is in 'deletion' mode. See https://goo.gl/coKwA7.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.TombstoneSweeper.SweepError"
    enum="LevelDBStatus" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Recorded on the browser side (back end) when the IndexedDB Tombstone Sweeper
    encounters an error while sweeping. See https://goo.gl/coKwA7.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.Transaction.ReadOnly.SizeOnCommit2"
    units="KB" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The total temporary size of an IndexedDB ReadOnly Transaction. Since this is
    a readonly transaction, the size should only be &gt;0 when the transaction
    is removing tombstone index keys. Recorded on transaction commit.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.Transaction.ReadOnly.TimeActive" units="ms"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The time it takes for an IndexedDB ReadOnly Transaction to commit, starting
    from when it starts executing tasks (when it is scheduled). Recorded on
    transaction commit.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.Transaction.ReadWrite.SizeOnCommit2"
    units="KB" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The total temporary size of an IndexedDB ReadWrite Transaction. This is the
    memory that is temporarily stored before writing to disk. Recorded on
    transaction commit.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.Transaction.ReadWrite.TimeActive" units="ms"
    expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The time it takes for an IndexedDB ReadWrite Transaction to commit, starting
    from when it starts executing tasks (when it is scheduled). Recorded on
    transaction commit.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.Transaction.VersionChange.SizeOnCommit2"
    units="KB" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The total temporary size of an IndexedDB VersionChange Transaction. This is
    the memory that is temporarily stored before writing to disk. Version change
    transactions happen when creating a database or updating a current database
    schema. Recorded on transaction commit.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.Transaction.VersionChange.TimeActive"
    units="ms" expires_after="2023-06-24">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    The time it takes for an IndexedDB VersionChange Transaction to commit,
    starting from when it starts executing tasks (when it is scheduled). Version
    change transactions happen when creating a database or updating a current
    database schema. Recorded on transaction commit.
  </summary>
</histogram>

<histogram name="WebCore.IndexedDB.TransactionAbortReason" enum="IDBException"
    expires_after="2023-08-27">
  <owner>ayui@chromium.org</owner>
  <owner>chrome-owp-storage@google.com</owner>
  <summary>
    Recorded on the browser side (back end) when an IndexedDB transaction is
    aborted, specifically recording the reason for the abort. This can be
    triggered by javascript code on the renderer, errors or force closes on the
    backend, or by the transaction timeout timer.
  </summary>
</histogram>

<histogram name="WebCore.ResourceFetcher.ActionUponResourceRequest"
    enum="ActionUponResourceRequest" expires_after="M85">
  <owner>clamy@chromium.org</owner>
  <summary>
    The resulting action (e.g. load resource, use resource from in-memory
    cache...) upon a resource request.
  </summary>
</histogram>

<histogram name="WebCore.ResourceFetcher.ResourceHasClientUponCacheHit"
    enum="ResourceHasClient" expires_after="M85">
  <owner>clamy@chromium.org</owner>
  <summary>
    Whether the resource in the cache is being used by at least one client (live
    resource) or not (dead resource) upon a cache hit.
  </summary>
</histogram>

<histogram name="WebCore.Scripts.Async.NotStreamingReason"
    enum="NotStreamingReason" expires_after="2023-10-08">
  <owner>leszeks@chromium.org</owner>
  <owner>v8-runtime@google.com</owner>
  <summary>Reason for not streaming an async script.</summary>
</histogram>

<histogram name="WebCore.Scripts.Async.StartedStreaming" enum="BooleanStreamed"
    expires_after="2023-08-08">
  <owner>leszeks@chromium.org</owner>
  <owner>v8-runtime@google.com</owner>
  <summary>Whether an async script was streamed or not.</summary>
</histogram>

<histogram name="WebCore.Scripts.Deferred.NotStreamingReason"
    enum="NotStreamingReason" expires_after="2023-10-08">
  <owner>leszeks@chromium.org</owner>
  <owner>v8-runtime@google.com</owner>
  <summary>Reason for not streaming a deferred script.</summary>
</histogram>

<histogram name="WebCore.Scripts.Deferred.StartedStreaming"
    enum="BooleanStreamed" expires_after="2023-06-01">
  <owner>leszeks@chromium.org</owner>
  <owner>v8-runtime@google.com</owner>
  <summary>Whether a deferred script was streamed or not.</summary>
</histogram>

<histogram name="WebCore.Scripts.InlineStreamerTimedOut" enum="BooleanTimedOut"
    expires_after="2023-08-08">
  <owner>cduvall@chromium.org</owner>
  <owner>leszeks@chromium.org</owner>
  <summary>
    Whether waiting for the background compile for an inline script timed out on
    the main thread. This is recorded each time an inline script streamer is
    available when executing an inline script.
  </summary>
</histogram>

<histogram name="WebCore.Scripts.InlineStreamerWaitTime" units="microseconds"
    expires_after="2023-10-01">
  <owner>cduvall@chromium.org</owner>
  <owner>leszeks@chromium.org</owner>
  <summary>
    Records the time the main thread is blocked while waiting for an inline
    script to finish compiling on a background thread. Recorded for each inline
    script that is compiled on a background thread.

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

<histogram name="WebCore.Scripts.Other.NotStreamingReason"
    enum="NotStreamingReason" expires_after="2023-10-08">
  <owner>leszeks@chromium.org</owner>
  <owner>v8-runtime@google.com</owner>
  <summary>
    Reason for not streaming an other (not async, deferred or parser blocking)
    script.
  </summary>
</histogram>

<histogram name="WebCore.Scripts.Other.StartedStreaming" enum="BooleanStreamed"
    expires_after="2023-06-01">
  <owner>leszeks@chromium.org</owner>
  <owner>v8-runtime@google.com</owner>
  <summary>
    Whether an other (not async, deferred or parser blocking) script was
    streamed or not.
  </summary>
</histogram>

<histogram name="WebCore.Scripts.ParsingBlocking.NotStreamingReason"
    enum="NotStreamingReason" expires_after="2023-10-08">
  <owner>leszeks@chromium.org</owner>
  <owner>v8-runtime@google.com</owner>
  <summary>Reason for not streaming a parsing blocking script.</summary>
</histogram>

<histogram name="WebCore.Scripts.ParsingBlocking.StartedStreaming"
    enum="BooleanStreamed" expires_after="2023-06-01">
  <owner>leszeks@chromium.org</owner>
  <owner>v8-runtime@google.com</owner>
  <summary>Whether a parsing blocking script was streamed or not.</summary>
</histogram>

<histogram name="WebCore.WebSocket.SendType" enum="WebSocketSendType"
    expires_after="2021-10-17">
  <owner>yhirano@chromium.org</owner>
  <owner>ricea@chromium.org</owner>
  <summary>
    Count the number of send() method calls on WebSockets for each argument
    type.
  </summary>
</histogram>

</histograms>

</histogram-configuration>