<!--
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 Variations histograms
along with a detailed description for each histogram.
For best practices on writing histogram descriptions, see
https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histograms/README.md
Please follow the instructions in the OWNERS file in this directory to find a
reviewer. If no OWNERS file exists, please consider signing up at
go/reviewing-metrics (Googlers only), as all subdirectories are expected to
have an OWNERS file. As a last resort you can send the CL to
[email protected].
-->
<histogram-configuration>
<histograms>
<histogram name="Variations.AppliedSeed.Size" units="bytes"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The size of the variations seed (serialized uncompressed proto) that is
loaded on startup and used. Note that not all loaded seeds are used; for
example, expired seeds are not used. The seed could be a regular seed or a
safe seed. Recorded after setting up field trials with the seed.
</summary>
</histogram>
<histogram name="Variations.AppliedSeed.StudyCount" units="studies"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The number of studies contained in the seed that is being used. Note that
the client may not participate in all studies due to study filtering. The
seed could be a regular seed or a safe seed. Recorded before setting up
field trials with the seed.
</summary>
</histogram>
<histogram name="Variations.AppSeedFreshness" units="minutes"
expires_after="2025-01-19">
<owner>[email protected]</owner>
<owner>src/android_webview/OWNERS</owner>
<summary>
The time interval between when a WebView-using app's copy of the variations
seed was written to its local app storage and when it was loaded for use.
This is different from Variations.SeedFreshness because it measures
freshness from when the app received its copy of the seed, not when the seed
was originally downloaded. Written every time the browser process
initializes, but not if there was an error reading the seed, or no seed
existed.
</summary>
</histogram>
<histogram name="Variations.ExtendedSafeMode.BeaconFileDeserializationError"
enum="JsonDeserializationError" expires_after="2025-01-26">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<component>1456342</component>
<summary>
The error code given by JSONFileValueDeserializer::Deserialize(). Emitted
during CleanExitBeacon initialization when the beacon file cannot be
deserialized. In other words, it is emitted whenever the "Not
deserializable" bucket of the BeaconFileStateAtStartup histogram is
emitted.
As of M102 for desktop and iOS and M103 for Android Chrome, any client may
emit this metric. Prior to this, the metric was emitted by only clients in
an enabled group that used the beacon file.
</summary>
</histogram>
<histogram name="Variations.ExtendedSafeMode.BeaconFileStateAtStartup"
enum="BeaconFileState" expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<component>1456342</component>
<summary>
The state of the beacon file and its contents, e.g. readable or not
deserializable. See the BeaconFileDeserializationError histogram for more
details on why the file was not deserializable. Emitted when the
CleanExitBeacon is initialized.
As of M102 for desktop and iOS and M103 for Android Chrome, any client may
emit this metric. Prior to this, the metric was emitted by only clients in
an enabled group that used the beacon file.
</summary>
</histogram>
<histogram name="Variations.ExtendedSafeMode.BeaconFileWrite"
enum="BooleanSuccess" expires_after="2025-02-04">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<component>1456342</component>
<summary>
Denotes whether the beacon file was successfully written. Recorded
immediately after Chrome tries to write the file.
As of M102 for desktop and iOS and M103 for Android Chrome, any client may
emit this metric. Prior to this, the metric was emitted by only clients in
an enabled group that used the beacon file.
</summary>
</histogram>
<histogram name="Variations.FieldTriamParamsLogInvalidValue"
enum="VariationsLogInvalidValue" expires_after="2024-09-01">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Logged whenever |base::LogInvalidValue| is called, i.e. whenever an invalid
value is used with a FeatureParam. This is normally due to a bad config
file. The logged value of this histogram is a hash of the study name
associated with the aforementioned feature.
</summary>
</histogram>
<histogram name="Variations.FirstRun.DeltaCompression"
enum="VariationsDeltaCompression" expires_after="2023-08-08">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/android_webview/OWNERS</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The state of the delta-compression when attempting to fetch a variations
seed via the java-based fetcher on Android. Records both the requested and
received delta compression values in one enumeration.
</summary>
</histogram>
<histogram name="Variations.FirstRun.SeedConnectTime" units="ms"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The latency of connection to the variations server when fetching an initial
variations seed during Android Chrome first run. This is included in the
Variations.FirstRun.SeedFetchTime measurement. Only considers cases where an
HTTP 200 result was received.
</summary>
</histogram>
<histogram name="Variations.FirstRun.SeedFetchResult"
enum="VariationsSeedFetchResult" expires_after="2024-11-01">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The result of attempting to fetch an initial variations seed during Android
Chrome first run. Records both the HTTP code and various error values in one
enumeration. Prior to M95, non-200 HTTP codes were counted as IOException.
Starting with M95, these codes are logged separately.
</summary>
</histogram>
<histogram name="Variations.FirstRun.SeedFetchTime" units="ms"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The latency of fetching an initial variations seed during Android Chrome
first run. Only considers cases where an HTTP 200 result was received.
</summary>
</histogram>
<histogram name="Variations.FirstRunResult" enum="VariationsFirstRunResult"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The result of attempting to import an initial variations seed during Android
Chrome first run. Logged from VariationsSeedStore::LoadSeed when seed prefs
do not exist.
</summary>
</histogram>
<histogram name="Variations.ForcedFieldTrialsAtStartupForInternalsPage"
enum="Boolean" expires_after="2025-01-26">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Reports whether any field trials were overridden with the metrics-internals
field trials tab. This is recorded once at startup.
</summary>
</histogram>
<histogram name="Variations.Headers.DomainOwner" enum="VariationsHeadersOwner"
expires_after="2024-04-01">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The owner of the top-level domain from which certain subframe-initiated HTTP
requests are made. It's logged after determining that (i) the request should
include variations headers, (ii) the request is from a subframe, and (iii)
TrustedParams are not present. It's logged before adding headers. It allows
us to verify whether non-render-thread-initiated requests, if any, lack
TrustedParams.
</summary>
</histogram>
<histogram name="Variations.Headers.ExperimentCount" units="units"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Records number of experiment ids in the X-Client-Data header at the time the
header is constructed.
</summary>
</histogram>
<histogram name="Variations.Headers.HasLowEntropySourceValue"
enum="BooleanPresent" expires_after="2024-12-30">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Whether the variations headers include the low-entropy source value.
Recorded at the time the headers are constructed or are updated.
</summary>
</histogram>
<histogram name="Variations.Headers.RequestContextCategory"
enum="VariationsHeadersRequestContextCategory" expires_after="2024-08-04">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Details about the request context in which an HTTP request is made. Logged
after determining that the request should include variations headers but
before adding the headers.
</summary>
</histogram>
<histogram
name="Variations.Headers.URLValidationResult{VariationsHeadersURLValidationResult}"
enum="VariationsHeadersURLValidationResult" expires_after="2023-11-01">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The result of whether to append Variations headers to a request. Logged when
when determining (i) whether the URL to which the request is being sent
should have a variations header and (ii) whether--after a redirect--the
request to which a variations header was added should have the variations
header removed. {VariationsHeadersURLValidationResult}
</summary>
<token key="VariationsHeadersURLValidationResult">
<variant name=".Append"
summary="Result when checking whether to append a header."/>
<variant name=".Remove"
summary="Result when checking whether to remove a header."/>
</token>
</histogram>
<histogram name="Variations.InvalidLayerReason"
enum="VariationsInvalidLayerReason" expires_after="2024-11-01">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Records the reason for rejecting an invalid layer. Recorded when processing
the variations seed at startup and when simulating a new seed.
</summary>
</histogram>
<histogram name="Variations.InvalidStudyReason"
enum="VariationsInvalidStudyReason" expires_after="2025-02-16">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Records the reason for rejecting an invalid study. Recorded when processing
the variations seed at startup and when simulating a new seed.
</summary>
</histogram>
<histogram name="Variations.LimitedEntropy.SeedRejectionReason"
enum="VariationsLimitedEntropySeedRejectionReason"
expires_after="2025-01-10">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Records the reason for rejecting a variations seed that contains a layer
with LIMITED entropy mode. This is recorded when calculating the entropy
usage for the studies constrained to the layer with LIMITED entropy mode.
</summary>
</histogram>
<histogram name="Variations.LimitedEntropyTrial.AshSeedIsValid.OnSyncToLacros"
enum="BooleanValid" expires_after="2025-01-07">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Whether the seed value to randomize the limited entropy synthetic trial is
valid. This is only emitted from LaCrOS clients when reading the seed value
from the Ash Chrome client.
</summary>
</histogram>
<histogram name="Variations.Limits.VariationKeySize.{Size}" units="KiB"
expires_after="2025-03-01">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The number of kilobytes of the variations crash keys, recorded every time
crash keys are updated. Crash keys larger than kVariationKeySize will be
truncated. The size of kVariationKeySize is controlled by the preprocessor
macro LARGE_VARIATION_KEY_SIZE. {Size};
</summary>
<token key="Size">
<variant name="Default"
summary=""Default" is recorded when
LARGE_VARIATION_KEY_SIZE is NOT defined."/>
<variant name="Large"
summary=""Large" is used when LARGE_VARIATION_KEY_SIZE is
defined."/>
</token>
</histogram>
<histogram name="Variations.LoadPermanentConsistencyCountryResult"
enum="VariationsPermanentConsistencyCountryResult"
expires_after="2024-11-01">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Records how the country code saved in prefs used for filtering permanent
consistency studies compares to the country code in the variations seed.
This is recorded each time the saved country code is loaded from the pref.
</summary>
</histogram>
<histogram name="Variations.LoadSeedSignature" enum="VariationSeedSignature"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The result of verifying the latest variations seed's signature, recorded
when the seed is loaded from Local State. Not recorded when running in safe
mode.
</summary>
</histogram>
<histogram name="Variations.PolicyRestriction"
enum="VariationsRestrictionPolicyValues" expires_after="2023-12-30">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Records the restrictions on how experiment variations are applied on the
client. This is recorded at start up.
This histogram is not interesting anymore but it is still used by test code
to verify that the respective log is properly applied so it will be kept in
the code even if not collected by the server anymore. TODO(crbug/1345624):
Clean this dependency up and remove the histogram.
</summary>
</histogram>
<histogram name="Variations.ResourceRequestsAllowed"
enum="VariationsResourceRequestsAllowedState" expires_after="2023-06-04">
<expired_intentionally>
Kept as a diagnostic metric.
</expired_intentionally>
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Counts the number of times the VariationsService is allowed or not allowed
to make a request due to the ResourceRequestAllowedNotifier. Useful for
debugging cases where variations seeds may not be getting fetched.
</summary>
</histogram>
<histogram name="Variations.SafeMode.LoadSafeSeed.Result"
enum="VariationsSeedLoadResult" expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Records whether the safe variations seed was successfully read from disk on
startup. Records a detailed reason on read failure. Only recorded when
attempting to run in safe mode.
Expired after M77 and revived in M93.
</summary>
</histogram>
<histogram name="Variations.SafeMode.LoadSafeSeed.SignatureValidity"
enum="VariationSeedSignature" expires_after="2024-04-28">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The result of verifying the safe variations seed's signature. Recorded when
the seed is loaded from disk. Only recorded when attempting to run in safe
mode.
Expired after M77 and revived in M93.
</summary>
</histogram>
<histogram name="Variations.SafeMode.StoreSafeSeed.Result"
enum="VariationsSeedStoreResult" expires_after="2025-07-15">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Records the result of attempting to store a safe variations seed (and all
associated metadata) on disk.
Expired after M77 and revived in M93.
</summary>
</histogram>
<histogram name="Variations.SafeMode.StoreSafeSeed.SignatureValidity"
enum="VariationSeedSignature" expires_after="2023-06-04">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The result of verifying the safe variations seed's signature. Recorded when
attempting to store the safe seed on disk.
Expired after M77 and revived in M93.
</summary>
</histogram>
<histogram name="Variations.SafeMode.Streak.Crashes" units="crashes"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The number of consecutive crashes observed by the VariationsService without
a single intervening successful seed fetch. Recorded during Chrome startup
when the MetricsStateManager's CleanExitBeacon is created.
Prior to M92, this was recorded when the SafeSeedManager was created.
</summary>
</histogram>
<histogram name="Variations.SafeMode.Streak.FetchFailures" units="failures"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The number of consecutive failed attempts to fetch a new seed by the
VariationsService. Recorded during Chrome startup when the SafeSeedManager
is created.
</summary>
</histogram>
<histogram name="Variations.SafeModeCachedFlags.Streak.Crashes" units="crashes"
expires_after="never">
<!-- expires-never: Needed to detect and evaluate severity of before-native crashes behind cached flags. -->
<owner>[email protected]</owner>
<owner>src/chrome/browser/flags/OWNERS</owner>
<summary>
The number of consecutive crashes observed by Android's CachedFeatureFlags
without a single intervening successful flag cache from native. Recorded the
first time a cached flag is checked.
Android only.
</summary>
</histogram>
<histogram name="Variations.SafeModeCachedFlags.{Event}"
enum="VariationsSafeModeCachedFlagsBehavior" expires_after="never">
<!-- expires-never: Needed to detect and evaluate severity of before-native crashes behind cached flags. -->
<owner>[email protected]</owner>
<owner>src/chrome/browser/flags/OWNERS</owner>
<summary>
What behavior of Safe Mode for CachedFlags (including not engaging it) was
performed.
{Event}
The ratio "Cached" / ("WillCache" - "Pause")
is the success rate for a given mode, and (100% - success rate) is the crash
rate.
Android only.
</summary>
<token key="Event">
<variant name="Cached"
summary=""Cached" is recorded at the point where flags were
cached from native to Shared Preferences."/>
<variant name="Engaged"
summary=""Engaged" is recorded at the point where whether
to engage safe mode is decided."/>
<variant name="Pause"
summary=""Pause" is recorded when the initialization flow
is aborted."/>
<variant name="WillCache"
summary=""WillCache" is recorded when the initialization
flow that should result in caching flags is entered."/>
</token>
</histogram>
<histogram name="Variations.SeedDateChange" enum="VariationsSeedDateChange"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Counts if a response from the variations server is the first response of the
day or not. This is counted when a new valid seed or a 304 is received. The
date line is computed in UTC and the times being compared are the server
time from the server response and the stored server time from the last
successful request.
</summary>
</histogram>
<histogram name="Variations.SeedFetchResponseOrErrorCode{ConnectionType}"
enum="CombinedHttpResponseAndNetErrorCode" expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
HTTP response codes and network error encountered by VariationsService when
attempting to fetch a variations seed from the server over an
{ConnectionType} connection.
</summary>
<token key="ConnectionType">
<variant name="" summary="HTTPS"/>
<variant name=".HTTP" summary="HTTP"/>
</token>
</histogram>
<histogram name="Variations.SeedFetchTimeOnFirstRun" units="ms"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The latency of fetching an initial variations seed during first run on
non-Android platforms. Only considers cases where an HTTP 200 result was
received.
The respective metric for Android's is Variations.FirstRun.SeedFetchTime.
</summary>
</histogram>
<histogram name="Variations.SeedFreshness" units="minutes"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The time interval between when the variations seed was downloaded and when
it was loaded for use.
Recorded after the seed is loaded for both regular seeds and safe seeds. Not
recorded for expired seeds or for seeds with an unknown download time, which
is typically a seed imported via first run. A seed that (a) was fetched over
30 days ago and (b) is older than the binary build time is considered
expired.
Prior to M93, this metric was recorded under slightly different conditions.
First, the metric was recorded for safe seeds--expired or not--as long as
they had download times. As of M93, it's no longer recorded for expired safe
seeds. Second, the metric was not previously recorded for regular seeds that
were older than 30 days, but as of M93, the freshness is recorded for seeds
that are older than 30 days and newer than the binary build time.
Prior to M99, this histogram would not be logged for first run seeds (where
they were not fetched by Chrome, but provided externally, such as part of
Chrome installation via Google Update). In M99+, this histogram will be
logged with a value of 0 minutes, so that the seed is considered fresh.
</summary>
</histogram>
<histogram name="Variations.SeedFreshnessDiff" units="minutes"
expires_after="2025-03-03">
<owner>[email protected]</owner>
<owner>src/android_webview/OWNERS</owner>
<summary>
Logs the difference between the age of the seed (Seed Freshness) and the
app's copy of the seed (App Seed Freshness). Seed Freshness is recorded when
seed is loaded for both regular and safe seeds and AppSeed Freshness is
recorded every time the browser process initializes. SeedFreshnessDiff is
recorded at the latter of these two events. In the case when a user's clock
is set incorrectly, or when a user changes their clock backwards in between
Chrome runs, the difference between the seed freshness and the app seed
freshness will be calculated and cached as long as both of them are greater
than 0. Nothing is emitted to this histogram if either seed freshness or app
seed freshness is zero or negative.
</summary>
</histogram>
<histogram name="Variations.SeedLoadBlockingTime" units="ms"
expires_after="2024-11-01">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<owner>src/android_webview/OWNERS</owner>
<summary>
Records the time spent blocking WebView startup to wait for the variations
seed. This is less than the entire time needed to load the seed, since
startup is only blocked if loading is not complete by the time the seed is
needed. This would ideally have a maximum value equal to the timeout in
VariationsSeedLoader, but there is no actual limit on how late that timeout
could fire. This is logged once per WebView startup, whether or not loading
the seed was successful.
</summary>
</histogram>
<histogram name="Variations.SeedLoadResult" enum="VariationsSeedLoadResult"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Records whether the latest variations seed was successfully read from local
state on startup. Records a detailed reason on read failure. Not recorded
when running in safe mode.
</summary>
</histogram>
<histogram name="Variations.SeedProcessingTime" units="ms"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Records how long it takes to load and apply a variations seed. Recorded only
when the seed is successfully loaded and applied. To help diagnose a
processing time increase, see whether Variations.AppliedSeed.Size and
Variations.AppliedSeed.StudyCount increased at the same time.
</summary>
</histogram>
<histogram name="Variations.SeedStoreResult" enum="VariationsSeedStoreResult"
expires_after="2025-07-15">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Records the result of storing the variations seed that was received from the
server. Also logs the types of data received (gzip, delta, etc).
</summary>
</histogram>
<histogram name="Variations.SeedUsage" enum="VariationsSeedUsage"
expires_after="2025-07-15">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Captures details about Chrome's attempt to use a VariationsSeed, e.g.
whether Chrome used a safe seed. Recorded once during Chrome startup after
attempting to load a seed and before field trials are created.
</summary>
</histogram>
<histogram name="Variations.StoreSeed.DataSize" units="KiB"
expires_after="2025-02-23">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The size of the variations seed data, which may be a partial (delta) or
compressed (gzip) payload, see Variations.SeedStoreResult.
</summary>
</histogram>
<histogram name="Variations.StoreSeed.Time" units="ms"
expires_after="2024-11-01">
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The UI thread run time of the VariationsSeedStore::StoreSeedData function.
</summary>
</histogram>
<histogram name="Variations.StoreSeedSignature" enum="VariationSeedSignature"
expires_after="2024-11-01">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The result of verifying the variations seed signature, recorded when the
variations seed is stored to Local State after being retrieved from the
server.
</summary>
</histogram>
<histogram name="Variations.TimeSinceLastFetchAttempt" units="minutes"
expires_after="2024-11-01">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
The time since the previous attempt to fetch the variations seed within the
same session, with 0 indicating that this is the first attempt. Recorded
when a variations seed fetch is attempted by the VariationsService.
</summary>
</histogram>
<histogram name="Variations.UserChannel" enum="UserChannels"
expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Log the user channel assigned at browser startup used for evaluating the
variations seeds.
</summary>
</histogram>
<histogram name="Variations.WebViewDownloadJobInterval" units="minutes"
expires_after="2025-01-19">
<owner>[email protected]</owner>
<owner>src/android_webview/OWNERS</owner>
<summary>
The time between the start of two consecutive WebView seed downloads by
WebView's service. This metric will not be written if seeds are never
downloaded.
</summary>
</histogram>
<histogram name="Variations.WebViewDownloadJobQueueTime" units="minutes"
expires_after="2025-01-19">
<owner>[email protected]</owner>
<owner>src/android_webview/OWNERS</owner>
<summary>
The delay between when a WebView seed download was scheduled by the service
with the JobScheduler and when it was executed.
</summary>
</histogram>
<histogram name="Variations.{Mode}CreateTrials.SeedExpiry"
enum="VariationsSeedExpiry" expires_after="2025-01-05">
<owner>[email protected]</owner>
<owner>[email protected]</owner>
<owner>src/base/metrics/OWNERS</owner>
<summary>
Stores the state of the loaded variations seed, e.g. not expired. Recorded
after the seed is loaded and before trials are created from the seed. Note
that seeds for which this metric is recorded may not be applied, e.g. when
the seed has expired.
{Mode}
</summary>
<token key="Mode">
<variant name=""
summary="Recorded for all successfully loaded seeds. Not recorded in
variations safe mode. Note that the concept of an expired
seed changed in M93. Prior to M93, expired seeds were those
that were more than 30 days old. As of M93, seeds that are
older than 30 days and older than the binary's build time
are considered expired."/>
<variant name="SafeMode."
summary="Recorded for safe seeds when Chrome attempts to run in
variations safe mode. This metric was added in M93."/>
</token>
</histogram>
</histograms>
</histogram-configuration>
Codebase Browser
chromium