The number of times v2 packaged apps are launched grouped by extension_misc::AppLaunchBuckets. See also Extensions.AppLaunch.

Whether DnsConfigService::OnConfigChange actually corresponded to a change in DnsConfig.

Duration of time between calls to DnsConfigService::InvalidateConfig.

Duration of time spent parsing DnsConfig.

Counts of results of parsing DnsConfig in DnsConfigServicePosix.

Whether DnsConfig was parsed successfully.

Counts of results of parsing DnsConfig in DnsConfigServiceWin.

Whether the first valid DnsConfig included a rogue nameserver.

Counts of specific error codes returned by DnsTask if a subsequent ProcTask succeeded, at the end of a streak of failures after which the DnsClient was disabled.

TRUE counts the events when a valid DnsConfig is received and used to enable DnsClient, while FALSE counts the events when DnsClient is disabled after a series of successful fallbacks from DnsTask to ProcTask.

Duration of time spent by ProcTask in failing fallback resolutions.

Duration of time spent by ProcTask in successful fallback resolutions.

Whether there was a valid DNS configuration at the start of a job which eventually completed successfully.

Whether DnsHosts were parsed successfully.

Whether DnsConfigService::OnHostsChange actually corresponded to a change in DnsHosts.

Duration of time between calls to DnsConfigService::InvalidateHosts.

Duration of time spent parsing DnsHosts.

Counts of results of parsing DnsHosts in DnsConfigServiceWin.

The size of the HOSTS file observed before each attempt to parse it.

Time elapsed between the time the HostResolverImpl::Job was created and the time the Job was started (using DnsClient).

Time elapsed between the time the HostResolverImpl::Job was created and the time the Job was started (using DnsClient). Includes only Jobs which had priority HIGHEST when started.

Time elapsed between the time the HostResolverImpl::Job was created and the time the Job was started (using DnsClient). Includes only Jobs which had priority IDLE when started.

Time elapsed between the time the HostResolverImpl::Job was created and the time the Job was started (using DnsClient). Includes only Jobs which had priority LOW when started.

Time elapsed between the time the HostResolverImpl::Job was created and the time the Job was started (using DnsClient). Includes only Jobs which had priority LOWEST when started.

Time elapsed between the time the HostResolverImpl::Job was created and the time the Job was started (using DnsClient). Includes only Jobs which had priority MEDIUM when started.

Time elapsed between the last time the priority of a HostResolverImpl::Job changed (when a Request was attached or detached) and the time the Job was started (using DnsClient).

Time elapsed between the last time the priority of a HostResolverImpl::Job changed (when a Request was attached or detached) and the time the Job was started (using DnsClient). Includes only Jobs which had priority HIGHEST when started.

Counts of results of parsing addresses out of DNS responses in successful DnsTransactions.

Counts of specific error codes returned by DnsTask if a subsequent ProcTask succeeded.

Duration of time taken by DnsTask in resolutions that failed. Excludes time spent in the subsequent fallback.

Counts of the overall results of using asynchronous DNS in HostResolverImpl. This only includes jobs started with valid DNS configuration and excludes synchronous resolutions (as IP literals, from cache, and from HOSTS).

Duration of time taken by DnsTask in resolutions that succeeded.

Same as AsyncDNS.ResolveSuccess, but limited to pure IPv4 lookups.

Same as AsyncDNS.ResolveSuccess, but limited to pure IPv6 lookups.

Same as AsyncDNS.ResolveSuccess, but limited to IPv4/IPv6 lookups.

Count of servers in DnsConfig. Recorded on every new DnsSession, which is created on DNS change.

Index in DnsConfig of the failing server, recorded at the time of failure.

Count of server failures after network change before first success in the DnsSession. Recorded at the time of first success.

Count of server failures after success until the end of the session. Server has reported success at some point during the session. Recorded at the end of the DnsSession.

Count of server failures before success. This is NOT the first success in the DnsSession. Recorded at the time of success.

Count of server failures without success until the end of the session. Server has never reported success during the DnsSession. Recorded at the end of the DnsSession.

The current server is "good" and does not have to be skipped.

Duration of time taken in failing calls to AddressSorter in dual-stack resolutions using DnsTask.

Duration of time taken in successful calls to AddressSorter in dual-stack resolutions using DnsTask.

The number of names from the search name list consumed during a successful transaction (QTYPE A only).

The number of names left on the search name list at the end of a successful transaction (QTYPE A only).

The number of names on the search name list at the start of a transaction (QTYPE A only).

Duration of time taken by DnsTCPAttempt in failed attempts. Excludes timeouts.

Duration of time taken by DnsTCPAttempt in successful attempts.

Difference between RTT and timeout calculated using Histogram algorithm.

Difference between timeout calculated using Histogram algorithm and RTT.

Difference between RTT and timeout calculated using Jacobson algorithm.

Difference between timeout calculated using Jacobson algorithm and RTT.

Duration of time that would be spent waiting for lost request using Histogram algorithm.

Duration of time that would be spent waiting for lost request using Jacobson algorithm.

Duration of time since a HostResolverImpl::Resolve request to the time a result is posted. Excludes canceled, evicted, and aborted requests. Includes cache hits (recorded as 0). Excludes speculative requests.

Duration of time taken in failing DnsTransactions. This includes server failures, timeouts and NXDOMAIN results.

Duration of time taken in successful DnsTransactions. This includes all NOERROR answers, even if they indicate the name has no addresses or they cannot be parsed.

Same as AsyncDNS.TransactionSuccess but limited to A query type.

Same as AsyncDNS.TransactionSuccess but limited to AAAA query type.

TTL of the resolved addresses, as in the response received from the server. For results served from local cache, the TTL is from the original response.

Duration of time taken by DnsUDPAttempt in failed attempts. Excludes timeouts.

Duration of time taken by DnsUDPAttempt in successful attempts. Includes responses arriving after timeout, if multiple attempts are allowed.

Duration of time since the last empty config result to the time a non-change OnConfigChange is received.

Duration of time since the last empty config result to the time a non-change OnHostsChange is received.

The result of DnsConfigService watch. Counts STARTED on every initialization and FAILED_* on any failure.

Measures the frequency of user interactions with the Autocheckout bubble, which prompts users to invoke Autocheckout on supported websites.

Measures the frequency of final states reached in Autocheckout buy flow.

The state of the Autocheckout dialog when it was dismissed.

Measures the time elapsed between when the user submitted the Autocheckout dialog and when the Autocheckout flow, or filling process, concluded.

Measures the time elapsed between when the user submitted the Autocheckout dialog and when the Autocheckout flow concluded, in cases where the flow failed.

Measures the time elapsed between when the user submitted the Autocheckout dialog and when the Autocheckout flow concluded, in cases where the flow succeeded.

The initial state of a user that's interacting with a freshly shown Autocheckout dialog.

User interactions with the Autofill popup shown while filling an Autocheckout dialog.

Measures the frequency of security warnings and errors in the Autocheckout dialog.

Measures the duration for which an Autocheckout dialog was shown.

Measures the duration for which an Autocheckout dialog was shown, in cases where the user ended up canceling out of the dialog.

Measures the duration for which an Autocheckout dialog was shown, in cases where the user ended up accepting the dialog.

Measures how users are interacting with the Autocheckout dialog UI.

Measures the duration of time it takes for the Autocheckout UI to be actionable by the user after it is shown.

Measures the frequency of errors in communicating with the Google Online Wallet server.

Measures the frequency of required user actions returned by the Google Online Wallet server.

Measures time taken to download the Autocheckout whitelist file.

Measures time taken to download the Autocheckout whitelist file in case the download was failed.

Measures time taken to download the Autocheckout whitelist file in case the download was succeeded.

The number of address suggestions shown in the Autofill popup.

Deprecated as of 3/2011, replaced by Autofill.CreditCardInfoBar.

The Autofill credit card info bar was accepted.

Deprecated as of 3/2011, replaced by Autofill.CreditCardInfoBar.

The Autofill credit card info bar was denied.

The relative frequency with which users accept, deny, or ignore the Autofill credit card info bar prompt.

Measures the adoption of the HTML autocomplete type hint specification (see http://is.gd/whatwg_autocomplete for more details). For each fillable form detected, logs whether that form includes author-specified type hints.

Time elapsed between the user's first interaction with a form and the form's submission, for an autofilled form.

Time elapsed between the user's first interaction with a form and the form's submission, for a non-autofilled form.

Time elapsed between form load and form submission, for an autofilled form.

Time elapsed between form load and form submission, for a non-autofilled form.

Tracks whether Autofill is enabled on page load for a page containing forms.

Tracks whether Autofill is enabled when Chrome launches.

Deprecated as of 3/2011, replaced by Autofill.StoredProfileCount.

The number of Autofill address profiles a user has.

Deprecated as of 3/2011, replaced by Autofill.Quality.

The quality of the AutoFill implementation.

The quality of the Autofill implementation.

The quality of Autofill's heuristic field type detection.

The quality of Autofill's heuristic field type detection, broken down by the specific field type. Fields with multiple possible types (based on the stored Autofill data) are logged as having ambiguous type.

The overall quality of the Autofill field type predictions.

The overall quality of the Autofill field type predictions, broken down by the specific field type. Fields with multiple possible types (based on the stored Autofill data) are logged as having ambiguous type.

The quality of the Autofill server's field type detection.

The quality of the Autofill server's field type detection, broken down by the specific field type. Fields with multiple possible types (based on the stored Autofill data) are logged as having ambiguous type.

TBD.

Deprecated as of 6/2011, replaced by Autofill.ServerExperimentId.Query.

The experiment ID received in response to an Autofill server query.

The experiment ID received at the time of an Autofill upload.

Deprecated as of 3/2011, replaced by Autofill.ServerQueryResponse.

The usefulness of AutoFill server information.

The usefulness of Autofill server information.

The number of Autofill addresses a user has stored, measured at launch time.

Measures the frequency of various events in the Autofill user interaction flow. By comparing frequencies, we can compute several interesting "user happiness" metrics.

Counts the number of simulataneously connected Bluetooth devices. Used to direct testing efforts, and by our UI team to determine appropriate UI sizes.

Records the method used to pair each Bluetooth Device. Used to direct our testing efforts.

Records the result of pairing each Bluetooth Device. Used to understand whether we are having significant problems with Bluetooth pairing and seeing errors more commonly than we should.

The count of cellular device activation failures (Chrome OS).

The count of cellular device activation tries (Chrome OS).

The count of cellular reconnect failures during activation (Chrome OS).

The count of cellular device reconnect tries during activation (Chrome OS).

The count of successful cellular plan established (Chrome OS).

The count of initiated cellular device setup starts (Chrome OS).

The count of failed cellular plan setup tries (Chrome OS).

The count of failed cellular plan purchases (Chrome OS).

The count of successfully completed cellular plan purchases (Chrome OS).

The length of time between a dangerous download appearing on the downloads shelf, and the "Discard" button being clicked.

The length of time between the external protocol dialog being shown and the "Launch Application" button being clicked.

The length of time between a download appearing on the download shelf, and the user opening it by clicking the item or pressing return.

Time between "Report and Discard" button being shown and it being clicked.

The length of time between a dangerous download appearing on the download shelf, and the "Keep" button being clicked.

Deprecated as of 4/2013, experiment confirmed correctness of our patch.

Counts how often the user writes or reads from the clipboard and whether the write was from an incognito window or not.

When parsing a cookie, indicates if control characters were present in any of the cookie values and if any of the cookie values were invalid. Specifically, checks that all of the parsed values are valid according to the valid token definition in Section 2.2 of RFC2616 which specifies a token must have no separators (i.e. no characters from the following string, ignoring the starting and ending single quote: '()<>@,;:\"/[]?={} \t') and no control characters.

The duration in seconds between a cookie getting evicted (due to the number of cookies exceeding a domain limit), and subsequently reinstated.

Indicates whether a cookie attribute pair was set with both a valid key and a valid attribute value or not. For the key, this implies that it was a valid token as defined in Section 2.2 of RFC2616 which specifies a token must have no separators (i.e. no characters from the following string, ignoring the starting and ending single quote: '()<>@,;:\"/[]?={} \t') and no control characters. For the value, this implies that it contained no control characters and no semicolon.

Indicates whether a cookie name was set with a valid token. A valid token is defined in Section 2.2 of RFC2616 which specifies a token must have no separators (i.e. no characters from the following string, ignoring the starting and ending single quote: '()<>@,;:\"/[]?={} \t') and no control characters.

Indicates whether a cookie value was valid or invalid when there was an attempt to set it, where a valid value is defined in RFC 6265 as ASCII characters excluding controls, whitspace, comma, semicolon, and backslash.

Chrome OS shelf clicks.

The type of archive file that Chrome OS cros-disks daemon is requested to mount.

The media type of removable device that Chrome OS cros-disks daemon is requested to mount.

The type of file system that Chrome OS cros-disks daemon is requested to mount.

Whether an extension has been wiped out.

How many external extensions get wiped out as a result of the Sideload Wipeout one-time initiative.

Whether any extension got wiped out as a result of the Sideload Wipeout one-time initiative.

The user selection in the Sideload Wipeout bubble, grouped by the UmaWipeoutHistogramOptions enum.

Deprecated.

The total time it takes to perform a payload IO operation, for the regular disk cache.

The attempt which completed after the job was already cancelled.

The attempt which completed after the job was already cancelled OR the attempt that has finished after host resolution was already completed by an earlier attempt.

Duration of time taken in OS resolutions for actual navigations. These attempts which completed after the job was already canceled OR after the job was already completed by an earlier attempt. Note that cached resolutions may provide low (0ms?) resolution times.

The attempt that has not resolved the host successfully.

The attempt that resolved the host first and the resolution was not successful.

The attempt that resolved the host first and the resolution was successful.

The attempt that has resolved the host successfully.

Duration of time taken in OS resolutions that succeeded and were requested for actual navigations. These attempts which completed after the job was already canceled OR after the job was already completed by an earlier attempt. Note that cached resolutions may provide low (0ms?) resolution times.

This histogram shows the time saved by having spawned an extra attempt, when the first attempt didn't finish before retry attempt.

The time left to expiration of an entry when it is removed while compacting the HostCache.

The time since expiration of an entry when it is removed while compacting the HostCache.

The time since expiration of an entry when it is removed on lookup.

Error status when an empty address list was found in OnLookupComplete().

When either a pre-resolution was not done recently enough to provide benefit, or the the corresponding pre-resolution is still pending, this histogram shows the duration of time used to resolve a hostname as not existing during a failed attempt to navigate to (GET) a URL. In newer versions, if the hostname has never been found as a link during a page scan, and it has a referring URL, then it is added to referrer list data structure (hoping we'll do better next time).

When either a pre-resolution was not done recently enough to provide benefit, or the the corresponding pre-resolution is still pending, this histogram shows the duration of the duration of time used to resolve a hostname to navigate to (GET) a URL. In newer versions, if the hostname has never been found as a link during a page scan, and it has a referring URL, then it is added to referrer list data structure (hoping we'll do better next time).

Time elapsed between the time the HostResolverImpl::Job was created and the time the Job was started (a getaddrinfo call was dispatched to the thread pool).

Time elapsed between the time the HostResolverImpl::Job was created and the time the Job was started (a getaddrinfo call was dispatched to the thread pool). Includes only Jobs which had priority HIGHEST when started.

Time elapsed between the last time the priority of a HostResolverImpl::Job changed (when a Request was attached or detached) and the time the Job was started (a getaddrinfo call was dispatched to the thread pool).

The duration of time used (most recently) to pre-resolve a hostname, when the prefetched resolution was apparently evicted from the cache. The included samples only list pre-resolution times when the later navigations/fetches took in excess of 15ms.

Replaced by DNS.PrefetchFoundNameL.

Deprecated 2/2010, and replaced by DNS.PrefetchResolution

The duration of time used by the DNS pre-resolving threads to resolve a host name via the network. Any resolutions that are faster than 15ms are considered to be local cache hits, not requiring network access, and are not included in this histogram. This histogram is most useful for estimating the typical cost of a name resolution, but it also estimates the total number of network-based resolutions induced by this feature. Not all these resolutions prove helpful (i.e., the user does not always actually visit the resolved hostnames).

Replaced by DNS.PrefetchNegativeHitL.

The duration of time saved due to DNS pre-resolving in the "name not found" case. Time "savings" shown in the histogram are defined to be the difference between the DNS pre-resolution duration, and the DNS resolution duration seen during a navigation. These cache hits only list events where the DNS pre-resolve duration for a host was in excess of 15ms (i.e., the network was consulted), and the actual DNS resolution (when a user attempted to navigate to a link with the same host name) took less than 15ms (i.e., the network was not consulted), which means the gain was a result of a "cache hit" in the OS cache. For some users with LANs, all negative results (even when the DNS cache might otherwise help) take about 2.5 seconds (due to timeouts for netbios broadcasts), and hence no savings are possible (or shown) for such users in this category.

Replaced by DNS.PrefetchPositiveHitL.

The duration of time saved due to DNS pre-resolving in the "name was found" case, and induced by either a page scan for a link or an omnibox entry by the user. Time "savings" shown in the histogram are defined to be the difference between the DNS pre-resolution duration, and the DNS resolution duration seen during a navigation. These cache hits only list events where the DNS pre-resolve duration for a host was in excess of 15ms (i.e., the network was consulted), and the actual DNS resolution (when a user attempted to navigate to a link with the same host name) took less than 15ms (i.e., the network was not consulted), which means the gain was a result of a "cache hit" in the OS cache.

The duration of time spent by a proposed resolution waiting in the queue to be resolved. This number is in addition to any DNS resolution time that may come later.

The duration of time saved due to DNS pre-resolving in the "name was found" case, and induced by predicting (using referrer lists) that a resolution was needed. Time "savings" shown in the histogram are defined to be the difference between the DNS pre-resolution duration, and the DNS resolution duration seen during a navigation. These cache hits only list events where the DNS pre-resolve duration for a host was in excess of 15ms (i.e., the network was consulted), and the actual DNS resolution (when a user attempted to navigate to a link with the same host name) took less than 15ms (i.e., the network was not consulted), which means the gain was a result of a "cache hit" in the OS cache.

When, due to congestion avoidance, a queued pre-resolution is abandoned (recycled) without actually being resolved, this histograms records the age in the queue of that entry. Only times over 2 seconds are recorded in this histogram.

Counts of successes and failures of OS resolutions in various categories.

Duration of time taken in OS resolutions for actual navigations. Note that cached OS resolutions may provide low (0ms?) resolution times.

Same as DNS.ResolveFail, but limited to pure IPv4 lookups.

Same as DNS.ResolveFail, but limited to pure IPv6 lookups.

Same as DNS.ResolveFail, but limited to IPv4/IPv6 lookups.

Duration of time taken in speculative OS resolutions. Note that cached OS resolutions may provide low (0ms?) resolution times.

Duration of time taken in speculative OS resolution that succeeded. Note that cached resolutions may provide low (0ms?) resolution times.

Duration of time taken in OS resolutions that succeeded and were requested for actual navigations. Note that cached resolutions may provide low (0ms?) resolution times.

Same as DNS.ResolveSuccess, but limited to pure IPv4 lookups.

Same as DNS.ResolveSuccess, but limited to pure IPv6 lookups.

Same as DNS.ResolveSuccess, but limited to IPv4/IPv6 lookups.

Deprecated as of 5/2013.

Counts of hits and misses in the DNS cache and DNS jobs pool of wasted HostResolverImpl::Jobs that could be avoided by always resolving using AF_UNSPEC.

In some cases, such as when content arrives with embedded references to other servers, the prefetch system can't (or doesn't) attempt to pre-resolve the hostnames. As an example, a visit to www.cnn.com will fetch content with references to about 12 additional hostnames, none of which are currently anticipated. Such resolutions are termed "Unexpected Resolutions," and the durations associated with those DNS resolutions are shown below. Future features may attempt to learn (from prior experience locally, or from server provided hints), what secondary hostname resolutions should be done when a primary resolution (or navigation) takes place. This histogram shows what the potential savings are that "remain on the table" until we employ some of these more advanced features.

In some cases, such as when content arrives with embedded references to other servers, or when a page (such as one in SSL) preclude scanning and prefetching, the prefetch system can't (or doesn't) attempt to pre-resolve the hostnames. As an example, a visit to www.cnn.com will fetch content with references to about 12 additional hostnames, none of which might be anticipated. Similarly, clicking on a link in an SSL page won't be anticipated (since scanning in not allowed by default). Such resolutions are termed "Unexpected Resolutions," and the durations associated with those navigation induced DNS resolutions are shown below. If a referring URL is available for the navigation, the relationship to the referring URL was recorded, and future navigations to the referring hostname would have induced a pre-resolution of hostname that caused an entry below. Such any entry may facilitate future listing in the ReferredPositiveHit histogram.

Time between starting and finishing DNS probe.

Time between starting and finishing DNS probe when NCN says we're offline.

Result of DNS probes sent by the probe service when NCN says we're offline.

Time between starting and finishing DNS probe when NCN says we're online.

Result of DNS probes sent by the probe service when NCN says we're online.

Result of DNS probes sent by the probe service.

Elapsed time of DNS probes that return PROBE_BAD_CONFIG.

Whether the only nameserver in the system DNS config was 127.0.0.1 when the probe result was BAD_CONFIG.

The result of the system probe job when the overall probe result was BAD_CONFIG.

The number of nameservers in the system DNS config when the probe result was BAD_CONFIG.

Elapsed time of DNS probes that return PROBE_NO_INTERNET.

Elapsed time of DNS probes that return PROBE_NXDOMAIN.

Elapsed time of DNS probes that return PROBE_UNKNOWN.

Number of certs loaded from domain bound cert database.

Time spent loading domain bound cert database.

The size, on disk, of the domain bound cert database as it is being loaded.

Time spent generating a domain bound cert.

Combined time for GetDomainBoundCert retrieval (both synchronous and asynchronous).

Time for asynchronous retrieval (from the GetDomainBoundCert call until completion callback is called).

Time for synchronous GetDomainBoundCert cert retrieval.

Result of GetDomainBoundCert function.

Whether the domain-bound certs sqlite database was killed succesfully when an unrecoverable error was detected.

Counts of SSL client sockets broken down by support for Domain Bound Certificates TLS extension. Counts only connections with full handshakes, resumed sessions are not counted.

Longest time spent by requests waiting for load of domain bound cert database.

Number of requests that waited for load of domain bound cert database.

The length of downloads for serves that accept byte ranges.

The length of downloads for serves that do not specify whether the accept ranges, or have invalid ranges specified.

The length of downloads for serves that do not accept ranges.

The actual bandwidth (per read) of a download.

Downloads extension API function calls.

Disk bandwidth (defined as total bytes divided by the amount of time blocked on write or close on the file descriptor) seen for a single download.

Overall bandwidth seen for the download. Note that this is measured at the point at which the file is written, and so will not take into account the time costs of activities that occur after file write is completed (e.g. safe browsing scanning).

The percentage of the potential bandwidth actually used (per read) of a download. An entry of 100% implies that Chrome was the limiting factor in download speed.

The number of downloads in history at the time it is cleared.

Content-Disposition header features. The presence of a Content-Disposition header, use of 'name', 'filename' and 'filename*' parameters, and string encoding schemes are counted for each unthrottled download. The total number downloads is Download.Counts[5] (Initiated and Unthrottled).

Types of images that are downloaded.

Content types that are downloaded.

Various individual counts in the download system; see DownloadCountType for details.

Various individual counts in the download system, for example the number of downloads blocked by throttling from the DownloadRequestLimiter.

User chose to save a download which was marked dangerous. Grouped by the type of danger.

Reason for dropping a record read in from the DB.

Number of downloads removed from the history at once.

How long it took to delete some downloads from history.

How long it took to delete some downloads from history, per download.

A download which was marked dangerous was discarded without the user directly choosing, because the browser was closed. Grouped by the type of danger.

The percentage of the available disk bandwidth that was used by the download. 100% indicates that the disk bandwidth was the limiting factor for the download.

User actions in chrome://downloads

The size of successfully completed downloads.

How the user interacts with the file chooser when doing a "Save As" for non-full-page saves.

The amount of time in milliseconds the file thread blocks for each set of buffers drained from the incoming pipe (ms).

The number of buffers in a call to DownloadManager::UpdateDownload.

The time between a download completing and the file being opened for the first time.

The number of items in the History database, at the time a new download is recorded.

The number of items in the History database, at the time a new download is recorded. Higher maximum, more buckets than Download.HistorySize.

Positive net error code that caused a download to be interrupted at the *end* of a download (when the number of bytes is known). This is only triggered when the total content size is known before any bytes are transferred, such as when a Content-Length header is supplied.

The reason that a download was interrupted at the *end* of a download (when the number of bytes is known). This is only triggered when the total content size is known before any bytes are transferred, such as when a Content-Length header is supplied.

Positive net error code that caused a download to be interrupted.

The excessive number of bytes which have been received at the time that a download is interrupted. This is only triggered when the total content size is known before any bytes are transferred, such as when a Content-Length header is supplied.

The reason that a download was interrupted.

The number of kilobytes received for a download at the time it is interrupted.

The reported total size in kilobytes for a download at the time it is interrupted. This is essentially the size reported by the Content-Length header. If no size is specified up-front, it is not recorded in the histogram. For example, a download transferred with chunked encoding will not be recorded.

The total number of bytes minus the received number of bytes at the time that a download is interrupted. This is only triggered when the total content size is known before any bytes are transferred, such as when a Content-Length header is supplied.

True if the size of an interrupted download is unknown, false if it is known.

Network error that produced a DOWNLOAD_INTERRUPT_REASON_NETWORK_FAILED result in DownloadResourceHandler::OnResponseCompleted().

Windows error that produced a DOWNLOAD_INTERRUPT_REASON_ACCESS_DENIED result in MapShFileOperationCodes().

Windows error that produced a DOWNLOAD_INTERRUPT_REASON_FILE_FAILED result in MapShFileOperationCodes().

Percentage of DownloadItem::Observer::OnDownloadUpdated events that signified a change in the extension API representation of the download.

The number of unopened downloads, when one is opened.

The time between a download completing and the file being opened.

The maximum bandwidth (per read) that Chrome could have provided for the download. If the actual bandwidth equals the potential bandwidth, that means that Chrome was the limiting factor for download bandwidth.

The percentage of the lifetime of the DownloadResourceHandler for which it was blocked by downstream flow control. 0% indicates that the network bandwidth was the limiting factor for the download.

Events (e.g. Started, Cancelled, Finished, Write to Completed file, Write to Failed file) occuring within the state machine of a SavePackage operation.

The number of download items in progress on the shelf when it closes automatically.

The number of download items in progress on the shelf when the user closes it.

The number of download items on the shelf when it closes automatically.

The number of download items on the shelf when the user closes it.

The initiation source (if initiated within the content layer of chrome) for a download.

The initiation source (if initiated within the above-content layer of chrome) for a download.

Time between the start of a download and its completion.

User chose to discard a download which was marked dangerous. Grouped by the type of danger.

The number of iterations for the write loop in BaseFile::AppendDataTofile().

The write size for calls to BaseFile::AppendDataTofile().

Status of drive cache metadata database open.

Time spent to load the entire file system information from the server

Provides breakdown of specific formats for hosted documents. Recorded when feed is loaded from the server.

Provides breakdown of specific file formats for regular files. Recorded when feed is loaded from the server.

Time spent to load the initial part of the file system information from the server

Result of drive resource metadata database initialization.

Result of attempt to open existing drive resource metadata database.

Number of hosted documents (spreadsheets etc.) on Drive. Logged when Drive is first accessed.

Number of regualr files on Drive. Logged when Drive is first accessed.

Number of total files (regualr files + hosted documents) on Drive. Logged when Drive is first accessed.

Tracks whether the push notification is initially enabled for Drive. Recorded when the first notification is processed. Notification is emulated by polling if the push notication is disabled.

Tracks whether the push notification request is registered correctly for Drive. Recorded when the push notification manager is initialized.

Time since the user logged in until the auto-enrollment protocol completed. 0 is sampled when the protocol is done by the time the user logs in.

Total duration time of the auto-enrollment protocol.

Network error code (if applicable) for auto-enrollment requests.

URL fetcher status for auto-enrollment requests.

Events related to fetching, saving and loading DM server tokens. These are used to retrieve cloud policies.

Events related to device enrollment on new installs of ChromeOS devices.

Result of the OpenNetworkConfiguration policy validation.

A set of enterprise policy rules that are in use. This is recorded every 24 hours and at startup, if the last recording was earlier than a day before.

Events related to fetching, saving and loading user policies, and also device policies on ChromeOS.

Load status from the policy loaders which pull policy settings from the underlying platform, such as Windows Group Policy.

The number of extensions that were blacklisted when already installed, grouped by Extension::Location. Logged when ExtensionService blackists and unloads an installed extension.

The number of extensions that have been blocked from installing grouped by Extension::Location. Logged when CrxInstaller refuses to install a blacklisted extension.

The number of extensions that were unblacklisted when installed, grouped by Extension::Location. Logged when ExtensionService unblacklists and loads a blacklisted extension.

Captures the results of URL resolution when relative urls are used in the tabs/windows api.

The number of times v1 apps are launched grouped by extension_misc::AppLaunchBuckets. See also Apps.AppLaunch for v2 apps.

The number of times apps are launched grouped by extension_misc::LaunchContainer.

The number of apps loaded at startup time grouped by Extension::Location.

The actions taken in the NTP apps promo grouped by extension_misc::AppsPromoBuckets.

The number of apps launched grouped by ExtensionPrefs::LaunchType.

The time for an extension's background page to load.

The type (if any) of background page the extension has. Recorded for installed extensions on startup.

Number of times chrome retried to download an extension with a url on a google.com domain, before eventually giving up.

Number of times chrome retried to download an extension with a url on a non google.com domain, before eventually giving up.

Number of times chrome retried to download an extension with a url on a google.com domain, before eventually succeeding.

Number of times chrome retried to download an extension with a url on a non google.com domain, before eventually succeeding.

Length of the path to the directory under which an extension is installed. This directory is in the user's profile.

Time spent until rules storage delegate gets ready.

Number of extensions referenced in the depricated external extensions source at path chrome::DIR_DEPRICATED_EXTERNAL_EXTENSIONS.

The time for a dialog-hosted extension to load.

The number of extensions that are disabled at browser startup.

The number of extensions that are disabled at browser startup due to permissions increases.

User response to the dialog shown when an extension is disabled due to an update requiring more permissions.

If opening the CRX file for unpacking fails, this integer is the error code given by the OS.

The time an extension's event page has spent loaded.

The time an extension's event page has spent unloaded.

The time for an extension's event page to load.

An extension has been installed.

The number of extensions loaded at startup time grouped by Extension::Location.

Length of the Extensions dir path inside the profile directory.

An extension has been uninstalled.

Records what happens to extensions that are sideloaded, grouped by the ExternalExtensionEvent enum.

Number of extensions referenced in the external extensions source at path chrome::DIR_EXTERNAL_EXTENSIONS.

Number of calls to extension functions.

What happens when the extensions system tries to get a temp dir to unpack in?

The amount of time for a CSS file to be injected into a page.

Number of scripts injected at document end by extensions.

Time taken to inject all scripts at document end by extensions.

Number of scripts injected at document idle by extensions.

Time taken to inject all scripts at document idle by extensions.

Time taken to inject all scripts by extensions.

Number of css files injected by extensions.

Number of scripts injected at document start by extensions.

Time taken to inject css/scripts at document start by extensions.

Installs grouped by the location property in prefs.

Installs grouped by Extension::HistogramType.

The number of extensions and themes loaded at browser startup.

Time taken to load all extensions at browser startup.

The number of apps loaded by each user at startup time.

The number of externally managed apps loaded by each user at startup time.

The number of user-installed apps loaded by each user at startup time.

The number of browser action extensions loaded at browser startup.

The number of content-pack extensions loaded at browser startup.

The number of extensions loaded at browser startup.

The number of externally managed extensions loaded at browser startup.

The number of user-installed extensions loaded at browser startup.

The number of externally managed extensions and apps loaded at browser startup.

The number of hosted apps loaded by each user at startup time.

The number of legacy packaged apps loaded by each user at startup time.

The number of page action extensions loaded at browser startup.

The number of platform apps loaded at browser startup.

The number of themes loaded at browser startup.

The number of extensions loaded at startup time grouped by Extension::HistogramType.

The number of converted user scripts loaded at browser startup.

Number of times chrome retried to download an extension update manifest with a url on a google.com domain, before eventually giving up.

Number of times chrome retried to download an extension update manifest with a url on a non google.com domain, before eventually giving up.

Number of times chrome retried to download an extension update manifest with a url on a google.com domain, before eventually succeeding.

Number of times chrome retried to download an extension update manifest with a url on a non google.com domain, before eventually succeeding.

Number of extension loads on startup where it is necessary to reload the mainfest because the locale has changed.

Number of extension loads on startup where it is not necessary to reload the extension's manifest.

Number of extension loads on startup where it is necessary to reload the manifest because the extension is unpacked.

Time that network requests were blocked due to extensions.

Percentage of total lifetime a network request was blocked due to an extension.

Time that network requests were blocked due to relevant rule registries loading.

The permissions present in an extension when it is automatically disabled due to a permission increase (e.g., after an extension upgrade).

The permissions present in an extension when it was installed.

The permissions present in an extension when installation was aborted, not including installation errors and user cancels.

The permissions present in an extension when installation was canceled.

The permissions present in an extension when it was loaded.

The permissions present in an extension when it was re-enabled from a confirmation prompt.

The permissions present in an extension when the re-enable prompt was aborted, not including installation errors and manual user cancels.

The permissions present in an extension when the re-enable was canceled from the confirmation prompt.

The permissions present in an extension when it was uninstalled.

The permissions present in an extension when it was installed through the web store.

The permissions present in an extension when installation from the web store was aborted, not including installation errors and user cancels.

The permissions present in an extension when installation from the web store was canceled.

Count the number of times a sandboxed extension unpack fails.

What caused a sandboxed extension unpack to fail?

Time taken to unpack an extension, when the unpack fails.

Length of the initial path to the CRX to be unpacked.

Length of the normalized (link/junction free) path to the temporary copy of a CRX made during unpacking.

Rate at which a CRX file is unpacked in Kilobytes per second.

Rate at which CRX files 1MB to 2MB are unpacked in Kilobytes per second.

Rate at which CRX files 2MB to 5MB are unpacked in Kilobytes per second.

Rate at which CRX files 50kB to 1MB are unpacked in Kilobytes per second.

Rate at which CRX files 5MB to 10 MB are unpacked in Kilobytes per second.

Rate at which CRX files larger than 10MB are unpacked in Kilobytes per second.

Rate at which CRX files under 50 KB are unpacked in Kilobytes per second.

Count the number of times a sandboxed CRX unpack succeeds.

Count the number of times a sandboxed CRX unpack succeeds, but we can't get the file size.

Time taken to unpack an extension, when the unpack succeeds.

Length of the path of the temporary copy of a CRX made during unpacking.

Length of the path under which a CRX is unpacked.

The time one extension delays network requests at startup.

The total time extensions delay network requests at startup.

Time taken to load a toolstrip.

Uninstalls grouped by Extension::HistogramType.

Count failing CRX installs, grouped by the way an extension can be installed.

Count successful CRX installs, grouped by the location property in prefs. installed.

Count successful CRX installs, grouped by the cause of the install.

Count successful CRX installs, grouped by the location property in prefs.

The number of legacy packaged apps and hosted apps that were checked during an update check.

The number of extensions that were checked during an update check.

Time in minutes between update checks.

The number of crx's with a Google-hosted update URL that were checked during an update check.

The number of crx's with no update URL checked during an update check.

The number of crx's with a non-Google update URL that were checked during an update check.

The number of packaged apps that were checked during an update check.

The number of themes that were checked during an update check.

The number of extensions that were updated at browser startup.

What happened when the extension updater tried to write a file?

Updates grouped by the location property in prefs.

Updates grouped by Extension::HistogramType.

Chrome OS File Browser opening mode.

Chrome OS File Browser: time to scan a directory. Measured on every File Browser directory change.

Tracks whether download destination is set to a Google Drive folder when the download destination is changed by the user in the settings page.

Tracks whether download destination is set to a Google Drive folder on startup.

Chrome OS File Browser: number of files and directories in the Downloads directory (not including the contents of nested directories). Computed every time the File Browser current directory changes to Downloads.

Chrome OS File Browser is an built-in extension without a background page. Its main.html file is loaded every time the user opens a File Browser tab or a file chooser dialog. The file is fairly large and the initialization is pretty expensive.

Deprecated 4/2013, and replaced by FileBrowser.ViewingFileType.

File types that were tried to be opened through browser.

Chrome OS Photo Editor: time to display an image. Measured from the moment the user selected the image till the moment it is displayed (not counting the low resolution preview).

Chrome OS Photo Editor: the type of the file opened.

Chrome OS Photo Editor: the way the image has been loaded.

Chrome OS Photo Editor: time to load an image from a file.

Chrome OS Photo Editor: the result of a file save operation.

Chrome OS Photo Editor: time to save an image to a file.

Chrome OS Photo Editor: size of an image file in megabytes. Measured on every image load.

Chrome OS Photo Editor: size of an image in megapixels. Measured on every image load.

Chrome OS Photo Editor: the button which the user clicked.

Chrome OS Photo Import flow: action chosen in the Action Choice dialog for the external device.

Chrome OS Photo Import flow: the number of photos imported. Measured on every successfull import operation.

Chrome OS Photo Import flow: the percent of photos imported among all the photos on the device. Measured on every successfull import operation.

Chrome OS Photo Import flow: time to load the action dialog. Measured between the moment window appears and the moment user see all available actions for the device.

Chrome OS Photo Import flow: time to scan the external device.

File types that were tried to be viewed through browser. This is recorded when the user tries to view a file from Files.app.

Result of the authentication for Drive.

Deprecated 9/2012, and replaced by Drive.EntireFeedLoadTime

Time spent to load the entire file system information from the server

Deprecated 9/2012, and replaced by Drive.EntryKind

Provides breakdown of specific formats for hosted documents. Recorded when feed is loaded from the server.

Deprecated 9/2012, and replaced by Drive.InitialFeedLoadTime

Time spent to load the initial part of the file system information from the server

Deprecated 9/2012, and replaced by Drive.NumberOfHostedDocuments

Number of hosted documents (spreadsheets etc.) on Drive. Logged when Drive is first accessed.

Deprecated 9/2012, and replaced by Drive.NumberOfRegularFiles

Number of regualr files on Drive. Logged when Drive is first accessed.

Deprecated 9/2012, and replaced by Drive.NumberOfTotalFiles

Number of total files (regualr files + hosted documents) on Drive. Logged when Drive is first accessed.

Events in Google Now component extension.

Histogram for usage of the section in the history page that allows the user to access tabs from other devices.

The time spent waiting for write lock on a disk cache entry.

Result of a main page HttpCacheTransaction if offline mode had been enabled.

Net error results from non-restartable cache read errors.

Net error results from restartable cache read errors.

The importer used on first run Auto Import.

The importer used on import from the bookmarks file API.

The importer used on import from the chrome://settings/importData UI.

The amount of time from install time to time that user opens import dialog from BookmarkBarView.

The amount of time from install time to time that user opens import dialog from NTP floating BookmarkBarView.

Deprecated and replaced by Import.ShowDialog.FromBookmarkBarView

The amount of time from install time to time that user opens import dialog from BookmarkBarView.

Deprecated and replaced by Import.ShowDialog.FromFloatingBookmarkBarView

The amount of time from install time to time that user opens import dialog from NTP floating BookmarkBarView.

Errors from update_engine process when running in dev mode.

The overhead in downloading extra bytes due to errors/interruptions. Expressed as a percentage of the bytes that are actually needed to be downloaded for the update to be successful.

The combinations of protocol and source server that were used to complete a successful update.

Errors from update_engine process when running in normal mode.

Number of MBs downloaded from during an update that completed successfully.

Total number of MBs downloaded since the last successful update. This also includes all the bytes downloaded during any prior failed attempts.

Absolute wallclock time duration it took for the update to complete from the time an update first began. It includes not just the time the device was up, but also includes the time the device spent sleeping.

Uptime duration it took for the update to complete from the time an update first began. It does not include the time the device spent sleeping, but it does include the uptime spent in waiting for the hourly update checks to happen.

Number of times the device was rebooted by the user since an update began and until it completed successfully.

Number of times the download URLs were switched due to failures.

Records various events of interest in the InstantController. E.g. When URLs are blacklisted.

How often an Instant preview is committed onto a different tab than it was created from.

The time between the first Omnibox interaction and when the Instant preview shows. If the instant preview was already showing when the user interacted with the omnibox, this histogram is not recorded.

Records the cause for falling back to a local overlay at the time of fallback.

Records a histogram for instant extended (Local NTP and Online NTP) and non-extended navigations.

Records, on startup, whether the user has chosen to opt-in to or opt-out of InstantExtended via chrome://flags.

Records, on startup, the value of the "Allow your search engine to provide Instant result" preference setting for the first profile loaded.

Accept languages.

Application languages used for UI.

Linux and CrOS use unlocked_stdio(3). If it is used unsafely, record it here. If there is no record of unsafety after chrome 29 has been in the stable channel for a few weeks then revert this change.

Methods where leveldb's Chromium environment has IO errors when being used by IndexedDB.

PlatformFileErrors encountered by a single leveldb env method.

Errno of errors encountered in NewLogger.

Errno of errors encountered in NewSequentialFile.

Deprecated 2013-04. As of m28 use LevelDBEnv.IDB.IOError.NewRandomAccessFile.

File errors in leveldb IDBEnv's NewRandomAccessFile method.

Errno of errors encountered in WritableFileAppend.

Errno of errors encountered in WritableFileFlush.

Number of directories missing when IDB LevelDBEnv tries to create a Lock file.

File descriptor limit recorded every time LevelDB calls NewRandomAccessFile for IndexedDB.

When IDB LevelDBEnv successfully retries an operation that had failed, record the error from the most recent failed attempt.

Deprecated 2013-04. As of m28 use LevelDBEnv.IDB.TimeUntilSuccessFor.

Time IDB LevelDBEnv slept before successfully completing this operation. 0 means success on the first try.

Methods where leveldb's Chromium environment has IO errors.

PlatformFileErrors encountered by a single leveldb method.

Errno of errors encountered in NewLogger.

Errno of errors encountered in NewSequentialFile.

Deprecated 2013-04. As of m28 use LevelDBEnv.IOError.NewRandomAccessFile.

File errors in leveldb ChromiumEnv's NewRandomAccessFile method.

Errno of errors encountered in WritableFileAppend.

Errno of errors encountered in WritableFileFlush.

Number of directories missing when Non-IDB LevelDBEnv tries to create a Lock file.

File descriptor limit recorded every time LevelDB calls NewRandomAccessFile for clients other than IndexedDB.

When Non-IDB LevelDBEnv successfully retries an operation that had failed, record the error from the most recent failed attempt.

Deprecated 2013-04. As of m28 use LevelDBEnv.TimeUntilSuccessFor.

Time Non-IDB LevelDBEnv slept before successfully completing this operation. 0 means success on the first try.

The version of glibc used. (Linux only)

Whether accelerated compositing was used for HTML5 media rendering.

Bits per channel of HTML5 audio sample data.

Audio channel layout in HTML5 media.

Audio codec used in HTML5 media.

Measures the time taken for AudioInputController::

Measures the time taken for AudioOutputController::

Time spent waiting in AudioOutputController::WaitTillDataReady() if the data was not initially available.

Captures statistics for various AudioRendererImpl events.

Percentage of AudioSyncReader::Read() calls where the renderer missed its realtime deadline.

Audio sample format in HTML5 media. Logged when Audio Decoder initializes.

Audio samples per second in HTML5 media.

Audio samples per second in HTML5 media (atypical values, in Hz).

Whether a media response might be used to satisfy a future request.

The average number of delayed and dropped frames for the ChromeCast application. Reported every 5 seconds.

The average number of displayed frames for the ChromeCast application. Reported every 5 seconds.

Time needed to pre-buffer A/V data before the actual playback for the ChromeCast application.

Time needed to buffer A/V data after an abort for the ChromeCast application.

Time needed to buffer A/V data after an underrun for the ChromeCast application.

Audio codec used in HTML5 media.

Container used for HTML5 media.

Video codec used in HTML5 media.

Measures the actions taken in the media infobar, which prompts the users for device permission.

Duration in milliseconds of HTML5 media (when known).

addKey result using the Clear Key key system.

cancelKeyRequest result using the Clear Key key system.

Decryption error event count using the Clear Key key system.

generateKeyRequest result using the Clear Key key system.

KeyAdded event count using the Clear Key key system.

KeyError event count using the Clear Key key system.

EME NeedKey event count.

addKey result using an unknown key system.

cancelKeyRequest result using an unknown key system.

Decryption error event count using an unknown key system.

generateKeyRequest result using an unknown key system.

KeyAdded event count using an unknown key system.

KeyError event count using an unknown key system.

addKey result using the Widevine key system.

cancelKeyRequest result using the Widevine key system.

Decryption error event count using the Widevine key system.

generateKeyRequest result using the Widevine key system.

KeyAdded event count using the Widevine key system.

KeyError event count using the Widevine key system.

Bits per channel of the hardware audio device which failed to open in low latency mode and required high latency fallback.

Channel count of the hardware audio device which failed to open in low latency mode and required high latency fallback.

Channel layout of the hardware audio device which failed to open in low latency mode and required high latency fallback.

Samples per second of the hardware audio device which failed to open in low latency mode and required high latency fallback.

Samples per second of the hardware audio device (atypical values, in Hz) which failed to open in low latency mode and required high latency fallback.

Whether Chrome had to fallback to the high latency audio path or not.

The average number of delayed and dropped frames for the Fling application. Reported every 5 seconds.

The average number of displayed frames for the Fling application. Reported every 5 seconds.

Time needed to pre-buffer A/V data before the actual playback for the Fling application.

Time needed to buffer A/V data after an abort for the Fling application.

Time needed to buffer A/V data after an underrun for the Fling application.

Results of attempts to GpuVideoDecoder::Initialize().

Bits per channel of the hardware audio device.

Channel count of the hardware audio device.

Channel layout of the hardware audio device.

Samples per second of the hardware audio device.

Samples per second of the hardware audio device (atypical values, in Hz).

The time it takes to perform redirect tracking and a CORS access check while preparing to play a media file.

Audio IO layer used by the Linux OS, sampled once at startup of the browser.

Audio codec used in Media Source Extensions playback. Set when AddId() is called during playback.

Number of tracks specified to AddId() for Media Source Extensions playback. May be called multiple times per element if playback is dynamically altered.

Whether Media Source Extensions is specified for playback of Media elements. Sampled when media pipeline starts.

Video codec used in Media Source Extensions playback. Set when AddId() is called during playback.

The audio bit rate as reported by the Netflix application. May be reported multiple times as network conditions change during playback.

The number of audio channels as reported by the Netflix application. May be reported multiple times as network conditions change during playback.

The average number of delayed and dropped frames for the Netflix application. Reported every 5 seconds.

The average number of displayed frames for the Netflix application. Reported every 5 seconds.

Video bit rate as reported by the Netflix application. May be reported multiple times as network conditions change during playback.

Video height as reported by the Netflix application. May be reported multiple times as network conditions change during playback.

Counts of video decode errors reported to plugin.

Number of PictureBuffers/textures requested per hardware decoder creation. This value varies by platform and video. A user visible video may trigger multiple decoder creations (sometimes every 5 seconds) but would normally not hold more than 2 sets of buffers at any given time in memory.

Vertical video resolution rounded to the nearest bucket. (Corresponds roughly to the number in 720p.)

The average number of delayed and dropped frames for the PlayMovies application. Reported every 5 seconds.

The average number of displayed frames for the PlayMovies application. Reported every 5 seconds.

Time in milliseconds from HTML5 media pipeline creation to playing event.

Size of HTML5 media (when known), in MB.

Reasons a media response won't be used to satisfy a future request.

URL scheme used with HTML5 media. (each URL provides one sample)

Error codes reported by video decode using VA-API hardware video decoder.

Video codec used in HTML5 media.

Video codec profile used in HTML5 media.

Coded aspect ratio of HTML5 video.

Coded width of HTML5 video.

Visible aspect ratio of HTML5 video.

Visible width of HTML5 video.

The average number of delayed and dropped frames for the YouTube application. Reported every 5 seconds.

The average number of displayed frames for the YouTube application. Reported every 5 seconds.

Time needed to pre-buffer A/V data before the actual playback for the YouTube application.

Time needed to buffer A/V data after an abort for the YouTube application.

Time needed to buffer A/V data after an underrun for the YouTube application.

The current process limit. Recorded once per UMA ping.

Value of getMemoryClass() recorded once upon startup. This is an integer, device-specific constant correlated with the amount of memory available on Android device.

Reasons behind evictions of individual tabs, recorded upon each tab eviction.

Number of loaded (memory-resident) tabs when LowMemory notification is delivered.

Time between two consecutive LowMemory notification in one foreground session.

Memory notifications delivered through system callbacks to Chrome while in the background.

Memory notifications delivered through system callbacks to Chrome while in the foreground - we count LowMemory notification vs particular levels of TrimMemory foreground notification.

Measures the time elapsed between when the user mousedown-ed a link and when the user clicked a link.

For each click handled by an HTML anchor tag link, whether Blink saw a mousedown event preceding it. This is only measured for clicks handled by the anchor tag's default click event handler.

The number of mousedown events detected at HTML anchor-tag links' default event handler.

Measures the time elapsed between when the user mouseover-ed a link and when the user clicked a link.

Measures the time elapsed between when the user mouseover-ed a link and when the user mouseout-ed a link without click.

The number of mouseover events detected at HTML anchor-tag links' default event handler.

The tap gesture events detected before click at HTML anchor-tag links' default event handler.

Measures the time elapsed between when the user tapdown-ed a link and when the user clicked a link.

The number of gesturetapdown events detected at HTML anchor-tag links' default event handler.

The number of gesturetapunconfirmed events detected at HTML anchor-tag links' default event handler.

The scheme of the URL for each main-frame navigation.

The count of unacknowledged ResourceMsg_DataReceived messages. This message is sent once per chunk of data read from the network.

The count of unacknowledged ResourceMsg_DataReceived messages at the point where we pause network loading.

The size of a SharedIOBuffer allocation.

The number of bytes copied into a SharedIOBuffer.

The percentage of a SharedIOBuffer allocation that is actually used.

The time to generate a Basic HTTP authentication token.

The time to generate a Digest HTTP authentication token.

The time to generate a Negotiate (or SPNEGO) HTTP authentication token.

The time to generate an NTLM HTTP authentication token.

Renamed to Net.PublicKeyPinSuccess 28 Oct 2011.

A validated certificate chain may be subject to additional "pinning" requirements on a per-domain basis. This records the fraction of successful matches between a certificate chain and a pin list.

The number of times we sent N packets, but could have sent N-1 packets.

The amount of time taken before we failed to resolve the Comodo test DNS record. This is an experiment, run in conjuction with Comodo, to test the viability of a DNS based certificate revocation mechanism.

The amount of time taken to successfully resolve the Comodo test DNS record. This is an experiment, run in conjuction with Comodo, to test the viability of a DNS based certificate revocation mechanism.

The uncompressed number of bytes received per request that was compressed. Only includes requests which did not go through an explicit proxy and did not go over SSL.

The compressed number of bytes received per request that was compressed. Only includes requests which did not go through an explicit proxy and did not go over SSL.

The uncompressed number of bytes received per request that was not compressed but appears to have been compressible. Only includes requests which did not go through an explicit proxy and did not go over SSL.

The uncompressed number of bytes received per request that was compressed. Only includes requests sent through a proxy without SSL.

The compressed number of bytes received per request that was compressed. Only includes requests sent through a proxy without SSL.

The uncompressed number of bytes received per request that was not compressed but appears to have been compressible. Only includes requests sent through a proxy without SSL.

The uncompressed number of bytes received per request that was compressed. Only includes requests sent over SSL.

The compressed number of bytes received per request that was compressed. Only includes requests sent over SSL.

The uncompressed number of bytes received per request that was not compressed but appears to have been compressible. Only includes requests sent over SSL.

The count was inaccurate (it counted transactions rather than connections)

Each bucket is the number of connections of a particular type that the user has had during the session.

Renamed to match HadConnectionType.

Each bucket is the number of successful connections of a particular type that the user has had during the session.

No longer collected.

Each bucket is the number of failed connections of a particular type that the user has had during the session.

Replaced by Net.ConnectionUsedSSLVersionFallback in Chrome 21.

True if the HTTP request was to a server which requires SSLv3 fallback

Nonzero if the HTTP request was to a server which requires SSL version fallback. The value indicates the SSL version the request fell back on.

Initial typo; only here to get results from builds before r59117. See "Cookie." group.

Whether or not updates to the backing store succeeded or failed, recorded every update.

Initial typo; only here to get results from builds before r59117. See "Cookie." group.

Intervals between access time updates for each cookie.

Initial typo; only here to get results from builds before r59117. See "Cookie." group.

Number of cookies in the store (recorded every 10 minutes of active browsing time)

Initial typo; only here to get results from builds before r59117. See "Cookie." group.

For each cookie removed from the store, the reason it was removed.

Initial typo; only here to get results from builds before r59117. See "Cookie." group.

For each domain, number of cookies in that domain (recorded every 10 minutes of active browsing time).

For every top level domain, number of subdomains in that top level domain (recorded every 10 minutes of active browsing time).

Initial typo; only here to get results from builds before r59117. See "Cookie." group.

For every top level domain, number of cookies in that domain (recorded every 10 minutes of active browsing time).

Initial typo; only here to get results from builds before r59117. See "Cookie." group.

For each evicted (not expired) cookie, the amount of time since it was last used

Initial typo; only here to get results from builds before r59117. See "Cookie." group.

Number of minutes until cookie expires when set.

Initial typo; only here to get results from builds before r59117. See "Cookie." group.

The amount of time (ms) to get cookies for each URL request.

Initial typo; only here to get results from builds before r59117. See "Cookie." group.

The amount of time (ms) to load the persistent cookie store at browser start.

The total number of severs to which alternative protocol was used. This counts the number of servers persisted to prefs file.

The total number of severs that support HTTP pipelining. This counts the number of servers persisted to prefs file.

The total number of SPDY server names persisted to prefs file.

The total number of SPDY Settings properties persisted to prefs file.

When validating an HTTPS certificate we may have to block to fetch one or more revocation lists. This measures the amount of time that failures to get CRL information take.

When validating an HTTPS certificate we may have to block to fetch one or more revocation lists. This records the fraction of successful requests.

When validating an HTTPS certificate we may have to block to fetch one or more revocation lists. This measures the amount of time that each fetch takes.

Measures time from initiating a fetch of a PAC file from DHCP WPAD to cancellation of the fetch. For a given fetch, only one of the cancellation or completion histograms will be added to.

Measures time from initiating a fetch of a PAC file from DHCP WPAD to completion of the fetch. For a given fetch, only one of the cancellation or completion histograms will be added to.

Tracks the net error codes received when the DHCP WPAD fetch fails to retrieve a PAC file (including PAC_NOT_IN_DHCP, which is not really an error but an indication that a PAC URL was not configured in DHCP).

Tracks the frequency of each of the different known error codes of calling the GetAdaptersAddresses Win32 API.

Measures the time taken to call the GetAdaptersAddresses Win32 API, to validate our understanding that it should complete quickly enough to call synchronously from the network thread.

Total number of adapters enabled for DHCP as seen when the wait timer in the DHCP WPAD code hits. This timer fires after a timeout from when we get some information from the first adapter to finish.

Number of adapters enabled for DHCP that we have not completed retrieving information for, as seen when the wait timer in the DHCP WPAD code hits. This timer fires after a timeout from when we get some information from the first adapter to finish.

Counts the number of errors from the DhcpRequestParams API that we do not have specific handling for, so that we can see if there is an abnormally high rate.

Deprecated- see Net.DNS_Resolution_And_TCP_Connection_Latency2 Deprecated- see Net.DNS_Resolution_And_TCP_Connection_Latency2

The time measured before starting DNS lookup until after the connection is complete.

Deprecated- see Net.DNS_Resolution_And_TCP_Connection_Latency2

The number of HTTP request responses with MS Office Docs MIME types. The responses are classified based on their method type and cacheability (POST, cacheable GET and non-cacheable GET). The histogram is used in Double GET Experiment, where successful non-cacheable GET requests are intercepted after initial response and repeated in order to determine how much reissuing non-cacheable GET requests influences their error rate. The histogram tracks only initial requests (not the repeated ones).

The response codes encountered for GET request repeated in Double GET Experiment. In the experiment successful non-cacheable GET requests are intercepted after initial response and repeated. The goal of the experiment is to measure how much reissuing non-cacheable GET requests influences their error rate.

Kbps on download streams exceeding 25KB. Measures from the beginning of the first byte received until the end of flowing data.

Net error codes that requests for images end with, including net::OK and net:ERR_ABORTED.

Deprecated as of 2011/5/24, replaced by Net.ErrorCodesForMainFrame2, which measures the same data but uses a different bucket structure (adds guard buckets).

Positive net error code that a page failed with. Note that this only counts the errors in "main frames", so it is a measure of the error pages that users actually see (it does not for example count the error codes for subresoures on a page).

Deprecated as of 2012/5/16, replaced by Net.ErrorCodesForMainFrame3, which measures the same data but includes ERR_ABORTED and OK.

Positive net error codes that requests for pages end with, including net::OK and net::ERR_ABORTED. This only counts loads in "main frames" (it does not for example count the error codes for subresoures on a page).

Deprecated as of 2012/5/16, replaced by Net.ErrorCodesForSubresources2, which measures the same data but includes ERR_ABORT and OK.

Positive net error code that a page failed with. Note that this only counts the errors in "subresources".

Net error codes that requests for "subresources" end with, including net::OK and net::ERR_ABORTED.

System error code that a file Flush failed with. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code that a file GetSize failed with. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code that a file Open failed with. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code that a file Read failed with. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code that a file Seek failed with. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code that a file SetEof failed with. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code that a file Write failed with. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code range that a file Flush failed with. Any value other than 0 indicates that we have received errors in a range outside of the one in which we recorded the specific errors in Net.FileError_Flush. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code range that a file GetSize failed with. Any value other than 0 indicates that we have received errors in a range outside of the one in which we recorded the specific errors in Net.FileError_GetSize. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code range that a file Open failed with. Any value other than 0 indicates that we have received errors in a range outside of the one in which we recorded the specific errors in Net.FileError_Open. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code range that a file Read failed with. Any value other than 0 indicates that we have received errors in a range outside of the one in which we recorded the specific errors in Net.FileError_Read. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code range that a file Seek failed with. Any value other than 0 indicates that we have received errors in a range outside of the one in which we recorded the specific errors in Net.FileError_Seek. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code range that a file SetEof failed with. Any value other than 0 indicates that we have received errors in a range outside of the one in which we recorded the specific errors in Net.FileError_SetEof. The code is OS dependent, so when looking at the histogram don't mix OSes.

System error code range that a file Write failed with. Any value other than 0 indicates that we have received errors in a range outside of the one in which we recorded the specific errors in Net.FileError_Write. The code is OS dependent, so when looking at the histogram don't mix OSes.

The number of times each FTP Error was observed.

The number of Chrome sessions which encountered the indicates FTP Error. This prevents allowing a user that retried a connection many times (getting an error each time) from biasing the tallies.

Each bucket is the number of FTP server types the user has encountered during the session.

The time spent waiting for WinHttpGetProxyForUrl to return with error.

The time spent waiting for WinHttpGetProxyForUrl to return with success.

Nonzero if the HTTP request was to a Google server which required SSL version fallback. The value indicates the SSL version the request fell back on. Since Google servers support TLS 1.2, any fallback is an indication of network middleware problems.

The count was inaccurate (it counted transactions rather than connections).

Each bucket is a boolean (0 or 1) indicating whether the user has had a connection of that type during the session.

This statistic measures successful and failed connections, the new one only measures successful ones.

Each bucket is a boolean (0 or 1) indicating whether the user has had a connection of that type during the session.

Each bucket is a boolean (0 or 1) indicating whether the user has had a successful connection of that type during the session.

Each bucket is a boolean (0 or 1) indicating whether the user has had a connection with an FTP server of that type during the session.

Per-authentication-scheme counts of authentication attempts and rejections.

Count of authentication requests for top level pages vs. sub-resources, such as images or iframes.

Per-authentication-scheme counts of authentication targets, such as secure servers or proxies.

Time between the HttpNetworkTransaction requesting a connection and the time it connected.

Size of the response body. This is the actual number of bytes received, which usually agrees with but is not necessarily the same as the size specified by the Content-Length header.

The difference between the size specified in the X-Original-Content-Length header and the size of teh response body. This is zero if the X-Original-Content-Length header is not present in the response.

The difference between the size specified in the X-Original-Content-Length header and the size of the response body. Only includes resources that have the X-Original-Content-Length header.

Size of the response body. Only includes resources that have the X-Original-Content-Length header.

Time it takes to complete an HttpJob, from starting the transaction until we are done reading.

Time it takes to complete an HttpJob, from starting the transaction until we are done reading, for jobs served from the cache.

Time it takes to complete an HttpJob, from starting the transaction until the job is killed. Note that we didn't detect the end of the data for this job.

Time it takes to complete an HttpJob, from starting the transaction until we are done reading, for jobs not served from the cache.

Time it takes to complete an HttpJob, from starting the transaction until we are done reading, for jobs when we read until no more data is available.

Size specified in the X-Original-Content-Length header. If this header is not present in the response, the size of the response body is used.

Size specified in the X-Original-Content-Length header. Only includes resources that have the X-Original-Content-Length header.

Time it takes to request a new (unused) HTTP proxy socket.

The count of HTTP Response codes encountered.

The count of HTTP Response codes encountered, in response to MAIN_FRAME requests only; saving only the hundreds digit, e.g. 100->1, 300->3.

The counts of the type of sockets (all HTTP sockets, regardless of any proxy used) used for HTTP[s].

Time from when an HTTP request is issued to when the first byte is processed.

The count of handleable socket errors (connection abort/close/reset) per socket reuse type.

Late bindings are on by default now.

The count of handleable socket errors (connection abort/close/reset) per socket reuse type. Socket late binding is disabled.

Late bindings are on by default now.

The count of handleable socket errors (connection abort/close/reset) per socket reuse type. Socket late binding is enabled.

Duration of time spent during the UDP-connect IPv6 probe.

Whether the the interface-enumeration IPv6 probe method failed given that the UDP-connect IPV6 probe failed.

Whether the the interface-enumeration IPv6 probe method was successful given that the UDP-connect IPV6 probe was successful.

The probe results when a test for IPv6 support is done.

The probe results when a test for IPv6 support is done, after a network change event.

The time that a (non-cancelled) proxy resolution request was stalled waiting for an execution thread, for MultiThreadedProxyResolver.

The total time that it took for a (non-cancelled) proxy resolution request to complete, for MultiThreadedProxyResolver.

How often automatically retrying to download the main frame of a page in response to specific HTTP network errors succeeds.

How often automatically retrying to download a subresource in response to specific HTTP network errors succeeds.

How often automatically retrying to download the main frame of a page in response to specific HTTP network errors returns another network error. Histogram includes only the error code that triggered the retry.

How often automatically retrying to download a subresource in response to specific HTTP network errors returns another network error. Histogram includes only the error code that triggered the retry.

On Windows, NetworkChangeNotifierWin calls NotifyAddrChange, which can fail for unknown reasons. This records the number of times it fails in a row before a successful call. If it never succeeds, or takes over 100 tries, a value of 100 is recorded. See http://crbug.com/69198

The number of duplicate cookies that were present in the cookie store during startup.

When validating an HTTPS certificate we may have to make one or more HTTP fetches to OCSP responders in order to get revocation information. This measures the amount of time that failures to get OCSP information take.

When validating an HTTPS certificate we may have to make one or more HTTP fetches to OCSP responders in order to get revocation information. This records the fraction of successful requests.

When validating an HTTPS certificate we may have to make one or more HTTP fetches to OCSP responders in order to get revocation information. This measures the amount of time that each of those requests takes.

Positive error code that was returned by the system library "getaddrinfo()". This error code is platform specific, so when there is a Windows/Linux conflict, both decodings are shown.

Positive error code that was returned by the system library "getaddrinfo()".

Indicate whether the navigation was preceded by a recent pre-connect (pre-connect within 10 seconds). There is a high chance that loading the page used a preconnected TCP session.

When a preconnection is made, indicate what the motivation was.

Currently, the most common (only?) motivations are SELF_REFERAL, LEARNED_REFERAL and OMNIBOX. The SELF_REFERAL indicates that we made sure a second connection was available for a resource that either was never before seen, or has historically had no subresources. The LEARNED_REFERAL indicates that we "learned" that a subresource was commonly needed, and that motivated the TCP/IP preconnect. The OMNIBOX motivation happens when a search is being suggested, and we preconnect to the search provider. (WARNING: Prior to version 7.517.*, enums 7, 8, and 9 may be confused, as EARLY_LOAD_MOTIVATED was inserted new 6 value.)

Indicate whether there was a proxy to preclude preconnection.

What did we decide to do about a predicted resource, based on the historical expected number of connection that this subresource will require.

This is basically the current thresholding of the SubresourceExpectation, relative to current static thresholds, and taking into account whether preconnection is enabled (i.e., if preconnection is disabled, we'll never decide to preconnect).

The expected number of connections, times 100, that we'll make to a given subresource, based on learned history.

By comparing this to thresholds, we decide if we will preconnect, preresolve, or do nothing. This histogram can be used to select those static thresholds.

Sourced data corrected, and replaced by NetPreconnectUtilization2

Indicate final utilization for each attempted socket connection.

We also include stats for non-speculative sockets. Some socket connections may never connect, and others may never be used (as the user may abort before then).

Indicate final utilization for each attempted socket connection.

We also include stats for non-speculative sockets. Some socket connections may never connect, and others may never be used (as the user may abort before then).

Replaced by Net.Priority_High_Latency_b.

Time from the start of the http transaction until the first byte of the response for high priority (currently frame and subframe) requests. Only times under 10 minutes are recorded.

Time from the start of the http transaction until the first byte of the response for high priority (currently frame and subframe) requests.

Replaced by Net.Priority_Low_Latency_b.

Time from the start of the http transaction until the first byte of the response for low priority (non-frame/subframe) requests. Only times under 10 minutes are recorded.

Time from the start of the http transaction until the first byte of the response for low priority (non-frame/subframe) requests.

The time in milliseconds spent fetch the system proxy configuration, when polling it for changes.

The total amount of time that was spent executing the proxy script during "tracing" runs (executions of the script which discovered a new DNS dependency and were subsequently abandoned).

The total amount of time that was spent in the non-blocking DNS bindings while executing PAC scripts. This includes the times for abandoned executions.

The amount of time inside of V8 that the proxy script spent executing for the final pass. This includes the time spent in the javascript bindings. This does not include the time spent in abandoned execution passes.

The number of times that alert() was called in the final execution of the script.

The number of errors that were seen in the final execution of the script.

The number of times that the PAC script execution was restarted.

The total time that the proxy resolution took. This includes all the time spent waiting for DNS, PAC script execution, and restarts.

The total time that proxy resolution spent waiting for DNS. This also includes any queuing delays on the origin thread waiting for the DNS result to be processed.

The number of unique DNS hostnames that the PAC script tried to resolve. The *Ex() versions of the bindings count separately.

The total amount of time that was spent in the non-blocking DNS bindings while executing PAC scripts. This includes the times for abandoned executions.

The amount of time inside of V8 that the proxy script spent executing for the final pass. This includes the time spent in the javascript bindings (which is probably dominated by Net.ProxyResolver.DnsWaitTotalTime). This does not include the time spent in abandoned execution passes.

The number of times that alert() was called in the final execution of the script.

The number of errors that were seen in the final execution of the script.

The number of times that the PAC script execution was restarted.

The amount of time it took upon completion to run the final task posted back to the IO thread.

The total time that the proxy resolution took. This includes all the time spent waiting for DNS, PAC script execution, and restarts.

The total time that proxy resolution spent waiting for DNS. This also includes any queuing delays on the origin thread waiting for the DNS result to be processed.

The total time that the proxy resolution took, not including the post back to the origin thread. This includes all the time spent waiting for DNS, PAC script execution, and restarts.

The number of unique DNS hostnames that the PAC script tried to resolve. The *Ex() versions of the bindings count separately.

The length of the URL that was passed into the PAC script.

Second-level domains for which we have observed public key pinning failures.

A validated certificate chain may be subject to additional "pinning" requirements on a per-domain basis. This records the fraction of successful matches between a certificate chain and a pin list.

The state of a QUIC connection's crypto hanshake as it progresses from starting to confirmation or failure.

The number of client hello messages sent.

The number of client hello messages sent when the crypto handshake was confirmed.

True if the HTTP request was sent to a server which supports the TLS renegotiation extension.

The time an already used socket sat idle before being used.

The time an unused socket (all HTTP sockets, regardless of any proxy used) sat idle before being used.

The time a previously used socket sat idle before encountering a recoverable socket IO error (connection abort/reset/close).

The time an unused socket sat idle before encountering a recoverable socket IO error (connection abort/reset/close).

Net error codes that socket initializations end with, including net::OK and net::ERR_ABORTED.

Time in milliseconds from initial RequestSocket() call until successfully acquiring a connected socket.

The time from the connection start to connection establish.

The time waiting to be ready to start connecting.

Each bucket is the number of connection type of socket stream.

The time a socket stream was open.

Each bucket is the number of protocol type on socket stream.

Number of bytes on a socket stream.

Number of reads on a socket stream.

Number of bytes on a socket stream.

Number of Write on a socket stream.

The counts of the type of sockets returned by the socket pools.

see SocketIdleTimeBeforeNextUse_ReusedSocket_SOCK

The time an already used SOCKS socket sat idle before being used.

see SocketIdleTimeBeforeNextUse_UnusedSocket_SOCK

The time an unused SOCKS socket sat idle before being used.

see SocketRequestTime_SOCK

Time from initial SOCKSClientSocketPool::RequestSocket() call until successfully acquiring a connected SOCKS socket.

Time it takes to request a new (unused) SOCKS proxy socket.

see SocketType_SOCK

The counts of the type of sockets returned by the SOCKS pool.

Time from when the Connect() starts until it completes.

The counts of the flow control state of each frame (with stream and session flow control on).

The counts of the flow control state of each frame (with stream flow control on).

Status of checking if a SPDY domain can handle a IP match. If a match is found, we successfully used the IP Pooling. If a match is not found, we could have used IP Pooling, except the TLS Cert didn't match the IP-pooled domain.

The RTT for SPDY's PING.

The count of streams at each priority over Spdy sessions.

The number of bytes recevied per stream.

The number of bytes sent per stream.

Total number of bytes recevied per session before closing session due to EOF.

Total number of bytes recevied per session before closing session due to an error during read.

Net error codes when SpdySession was closed, doesn't inlcuding net::OK.

Socket connected status in SpdySession::CreateStream.

Replaced by SpdySessionErrorDetails2 on 2013-04-19.

WARNING: r181910 added an enum value in the middle, so don't trust the counts for values 9 and above for Chrome builds after that revision. The type of SPDY Protocol error encountered.

The type of SPDY Protocol error encountered.

Replaced by SpdySessionErrorDetails_Google2 on 2013-04-19.

The type of SPDY Protocol error encountered when talking to a google.com server.

WARNING: r181910 added an enum value in the middle, so don't trust the counts for values 9 and above for Chrome builds after that revision. The type of SPDY Protocol error encountered when talking to a google.com server.

The type of SPDY Session used when looking up a session.

Whether SpdySession::Get{Peer,Local}Address was called when the connection had no socket.

SpdySession::GetLocalAddress returned ERR_SOCKET_NOT_CONNECTED.

SpdySession::GetPeerAddress returned ERR_SOCKET_NOT_CONNECTED.

The count of SPDY Sessions with or without stalls.

The congestion window (in pkts) received at the end of a SpdySession.

The congestion window (in pkts) sent at the beginning of a SpdySession.

Percentage of sessions which received settings from the server.

The Download Retransmission Rate (%) received at the end of a SpdySession.

The RTT received at the end of a SpdySession.

Percentage of sessions which sent settings to the server.

The time between receiving the the first chunk and the last chunk of data on a Spdy stream.

The number of pushed, but abandoned streams over a single session.

The number of streams issued over a single session.

The number of pushed, and used streams over a single session.

The number of push streams received over a single session.

The number of stream stalls per session.

The time of a Spdy stream. Measured from sending the first chunk to receiving the last chunk of data.

The time between sending the request and receiving the first chunk of data on a Spdy stream.

The percent compression achieved when compression SYN_STREAM frames.

The SPDY protocol version that is used to talk to SPDY servers.

Time from when the Connect() starts until it completes.

Time from when the Connect() starts until it completes for google.com and any subdomain of it.

Time from when the Connect() starts until it completes for google.com and any subdomain of it. This only includes users in a 50% field trial that disables revocation checking for certificate pinned sites.

Time from when the Connect() starts until it completes for google.com and any subdomain of it. This only includes users not in a 50% field trail that disables revocation for certificate pinned sites.

Counts the number of times that users have hit blacklisted certificates. The indexes match up to the indexes in net/base/x509_certificate.cc:IsBlacklisted. The details of the certificates in question is confidential.

Time to complete a certificate verification (success case).

Time to complete a certificate verification (error case).

Time to complete a DNS lookup for a DNS CAA record.

Time that we would have wasted had we waited for a CAA lookup in order to validate a certificate.

Time to complete a speculative certificate verification.

The number of times that we have performed SSLv3 fallback and found a TLS renegotiation patched server.

Was a speculative certificate verification used?

Time saved by a speculative certificate vertification.

Number of idle sockets when the Connect() succeeded.

Time from when the Connect() starts until it completes. Only times under 10 minutes are logged.

Time from when the Connect() starts until it completes when the network address only contains IPv4 addresses. Only times under 10 minutes are logged.

Time from when the Connect() starts until it completes when the IPv4 fallback connection won the race against IPv6. Only times under 10 minutes are logged.

Time from when the Connect() starts until it completes when we race an IPv6 connection against an IPv4 connection with a 300ms delay. Only times under 10 minutes are logged.

Time from when the Connect() starts until it completes when the network address only contains IPv6 addresses. Only times under 10 minutes are logged.

For sockets for which a TCP Fast Open protocol might be used, the result of trying to use it.

see SocketIdleTimeBeforeNextUse_ReusedSocket_TCPforSOCKS

The time an already used TCP socket sat idle before being used for a SOCKS request.

see SocketIdleTimeBeforeNextUse_UnusedSocket_TCPforSOCKS

The time an unused TCP socket sat idle before being used for a SOCKS request.

see SocketRequestTime_TCPforSOCKS

Time from initial SOCKSClientSocketPool::RequestSocket() call until successfully acquiring a connected TCP socket.

see SocketType_TCPforSOCKS

The counts of the type of sockets returned by the TCP pool used by the SOCKS pool.

Was only used for HTTP[S] connections, renamed to Net.HTTPSocketType.

The counts of the type of TCP socket returned.

(discontinued as of 4/12/09) Effective bandwidth in KByte/Second of transactions logged to Transaction_Latency histogram. Note that only samples durations greater than zero ms, and less than 1 hour are tallied into this ratio.

Time from the when the network transaction is requested, until the first byte of the header is received.

Replaced by Net.Transaction_Connected_New_b.

When a new connection is established, the time from the when the network transaction is requested, until the first byte of the header is received. Only items under 10 minutes are logged.

When a new connection is established, the time from the when the network transaction is requested, until the first byte of the header is received.

Replaced by Net.Transaction_Connected.

Time from the when the network transaction is requested, until the first byte of the header is received. Only items under 10 minutes are logged.

Replaced by Net.Transaction_Latency_b.

Time from first byte sent until last byte received by the new network stack. Only items under 1 hour are logged.

Time from first byte sent until last byte received by the new network stack.

Time from when a network transaction is requested until last byte received by the new network stack.

When an existing TCP/IP connection is NOT reused, the time from when a network transaction is requested until last byte received by the new network stack.

Replaced by Net.Transaction_Latency_Total_New_Connection.

When an existing TCP/IP connection is NOT reused, the time from when a network transaction is requested until last byte received by the new network stack. Only items under 10 minutes are logged.

Replaced by Net.Transaction_Latency_Total.

Time from when a network transaction is requested until last byte received by the new network stack. Only items under 10 minutes are logged.

Replaced by Net.Transaction_Latency.

Time from first byte sent until last byte received by the new network stack. Only items under 10 minutes are logged.

Time from first byte sent until last byte received with old WinHTTP network stack. Only items under 1 hour are logged.

The time an already used TCP socket sat idle before being used (either for direct or non-socks use).

The time an unused TCP socket sat idle before being used (either for direct or non-socks use).

Time from initial ClientSocketPool::RequestSocket() call until successfully acquiring a connected socket (either for direct or non-socks use).

The counts of the type of sockets returned by the TCP pool (either for direct or non-socks use).

The time spent in closesocket call in UDPSocketWin::Close.

The number of Wi-fi adapters on the computer. Because the histogram is logged each time Chrome performs a Wi-fi scan, it's better to see results in the "user count" view.

The time that a request to Location Based Services takes.

The time that a Wi-fi scan takes.

The network error, if any, of the first pipeline connectivity request.

The HTTP response code, if any, of the first pipeline connectivity response.

The result of the first pipeline connectivity request.

The network error, if any, of the second pipeline connectivity request.

The HTTP response code, if any, of the second pipeline connectivity response.

The result of the second pipeline connectivity request.

The network error, if any, of the third pipeline connectivity request.

The HTTP response code, if any, of the third pipeline connectivity response.

The result of the third pipeline connectivity request.

The network error, if any, of the fourth pipeline connectivity request.

The HTTP response code, if any, of the fourth pipeline connectivity response.

The result of the fourth pipeline connectivity request.

The network error, if any, of the fifth pipeline connectivity request.

The HTTP response code, if any, of the fifth pipeline connectivity response.

The result of the fifth pipeline connectivity request.

The network error, if any, of the stats pipeline connectivity request.

The HTTP response code, if any, of the stats pipeline connectivity response.

The result of the stats pipeline connectivity request.

True if all requests received by the pipelining test server were HTTP/1.1.

True if the non-pipelined canary request sent immediately before the pipelining test requests succeeded. Note that if this fails, the rest of the NetConnectivity.Pipeline.* stats are not collected.

The maximum depth of pipelined requests received by the test server.

True if the entire pipeline connectivity trial passed.

Deprecated 6/25/2012. No longer tracked.

In this experiment, 21 packets were sent to Google via UDP at port 6121 as rapidly as possible, just after successfully sending an UMA upload. Each packet was numbered, as was its ACK sent back by Google. If no packets (of the 21) were ever ACKed, then the port is assumed to be blocked, and no data is recorded in this histogram. If the port is not blocked, then this histogram shows the number of echo responses received from the first

Deprecated 6/25/2012. No longer tracked.

In this experiment, 21 packets were sent to Google via UDP at port 6121 as rapidly as possible, just after successfully sending an UMA upload. If no packets (of the 21) were ever ACKed, then the port is assumed to be blocked. The histogram shows if we ever got an ACK for a packet in our series of 21.

Deprecated 4/2012. No longer tracked.

The RTT for echoing 100 bytes of TCP data unsuccessfully.

Deprecated 4/2012. No longer tracked.

The RTT for echoing 1K bytes of TCP data successfully.

Status for TCP protocol for echoing

Deprecated 4/2012. No longer tracked.

Status for echoing 100 bytes of TCP data.

Deprecated 4/2012. No longer tracked.

Status for echoing 1K bytes of TCP data.

The RTT for TCP protocol for echoing

Deprecated 4/2012. No longer tracked.

The RTT for echoing 100 bytes of TCP data successfully.

Deprecated 4/2012. No longer tracked.

The RTT for echoing 1K bytes of TCP data successfully.

Deprecated 4/2012. No longer tracked.

The RTT for echoing 100 bytes of UDP data unsuccessfully.

Deprecated 4/2012. No longer tracked.

The RTT for echoing 1K bytes of UDP data successfully.

Deprecated 6/25/2012. No longer tracked.

Chrome sends 4 UDP packets in a row to test to see if there is a probabalistic dependency in packet loss for consecutive packets. We record a bit vector of packets received, where the least significant bit is a 1 if the first packet was received, etc. For example, if packets 1 and 3 are received, but packets 2 and 4 are lost, then we'd record a sample of binary 0101B, or 5.

Deprecated 6/25/2012. No longer tracked.

Chrome sends 6 UDP packets in a row to test to see if there is a probabalistic dependency in packet loss for consecutive packets. We record a bit vector of packets received, where the least significant bit is a 1 if the first packet was received, etc. For example, if all packets other than packet 2 and 4 are responded to, then we'd have a sample (in binary) of 110101B, or 53.

Status for UDP protocol for echoing

Deprecated 4/2012. No longer tracked.

Status for echoing 100 bytes of UDP data.

Deprecated 4/2012. No longer tracked.

Status for echoing 1K bytes of UDP data.

The RTT for UDP protocol for echoing

Deprecated 4/2012. No longer tracked.

The RTT for echoing 100 bytes of UDP data successfully.

Deprecated 4/2012. No longer tracked.

The RTT for echoing 1k bytes of UDP data successfully.

This histogram records how many packets (out of 6 attempted) were sent via UDP as rapidly as possible, just after successfully sending an UMA upload.

In this experiment, 21 packets were sent to Google via UDP as rapidly as possible, just after successfully sending an UMA upload. Each packet was numbered, as was its ACK sent back by Google. If no packets (of the 21) were ever ACKed, then the port is assumed to be blocked, and no data is recorded in this histogram. If the port is not blocked, then this histogram shows the number of echo responses received from the first

In this experiment, 21 packets were sent to Google via UDP as rapidly as possible, just after successfully sending an UMA upload. If no packets (of the 21) were ever ACKed, then the port is assumed to be blocked. The histogram shows if we ever got an ACK for a packet in our series of 21.

This histogram records how many packets (out of 21 attempted) were sent via UDP as rapidly as possible, just after successfully sending an UMA upload.

In this experiment, 21 packets were sent to Google via UDP on port 443 or 6121.

Deprecated 9/2012. No longer tracked.

This histogram records how many packets (out of 6 attempted) were sent via UDP as rapidly as possible, just after successfully sending an UMA upload.

The time the Gobi modem takes to complete activation.

The time the Gobi modem takes to connect to the cellular network.

The time the Gobi modem takes to disconnect from the cellular network.

Number of attempts taken to install Gobi firmware.

The time it takes to install Gobi firmware.

The time the Gobi modem takes to register on the cellular network.

Errors experienced during Gobi device powerup.

Chrome OS network metric sampling the time spent using Cellular to transport data. These data are mostly useful when summed and compared to TimeOnline for other network technologies (e.g. WiFi vs Cellular).

Chrome OS network performance metric sampling the time to join a 3G/Cellular network and configure Layer 3 state.

Chrome OS network performance metric sampling the time to determine that a 3G/Cellular network is online after configuring Layer 3 state.

Chrome OS network performance metric sampling the time to determine that a 3G/Cellular network is in a captive portal after configuring Layer 3 state.

Chrome OS cellular usage API request status codes.

Chrome OS network metric sampling the time spent using Ethernet to transport data. These data are mostly useful when summed and compared to TimeOnline for other network technologies (e.g. WiFi vs Cellular).

Chrome OS network performance metric sampling the time to join a wired Ethernet network and configure Layer 3 state (typically acquire a DHCP lease).

Chrome OS network performance metric sampling the time to determine that an Ethernet network is online after configuring Layer 3 state.

Chrome OS network performance metric sampling the time to determine that an Ethernet network is in a captive portal after configuring Layer 3 state.

Chrome OS connection manager service errors seen.

Chrome OS network diagnostic metric sampling the total amount of time spent from the start of the first auto-connect request until when the cellular modem successfully connects to the network.

Chrome OS network diagnostic metric sampling the number of auto-connect tries that were attempted before the cellular modem successfully connected to the network.

Chrome OS network usage metric that tracks whether the cellular network was disconnected due to an error or was explicitly disconnected by the user.

Chrome OS cellular network metric that tracks the number of drops based on the network technology.

Chrome OS cellular network metric that tracks the number of out-of-credits detected based on the cause that triggered the out-of-credits.

Chrome OS network diagnostic metric sampling the number of portal detection attempts per pass for a cellular network. This includes failure, timeout and successful attempts.

Chrome OS network diagnostic metric sampling the total number of portal detection attempts performed for a cellular network between the Connected and Online state. This includes failure, timeout and successful attempts.

Chrome OS network diagnostic metric sampling the result of portal detections for a cellular network.

Chrome OS network metric sampling the signal strength (0-100) of the cellular modem before it dropped from the network.

Chrome OS network metric sampling the time spent using cellular to transport data. These data are mostly useful when summed and compared to TimeOnline for other network technologies (e.g. WiFi vs Cellular).

Chrome OS network performance metric sampling the time to join a cellular network and configure Layer 3 state.

Chrome OS network performance metric sampling the time to connect a cellular modem.

Chrome OS network performance metric sampling the time to disable a cellular modem.

Chrome OS network performance metric sampling the time to enable a cellular modem.

Chrome OS network performance metric sampling the time to initialize a cellular modem.

Chrome OS network performance metric sampling the time to determine that a cellular network is online after configuring Layer 3 state.

Chrome OS network performance metric sampling the time to determine that a cellular network is in a captive portal after configuring Layer 3 state.

Chrome OS network performance metric sampling the time to scan a cellular network and register a modem.

Chrome OS cellular network metric that tracks the number of corrupted profiles encountered by Shill.

Chrome OS network usage metric that tracks whether the Ethernet network was disconnected due to an error or was explicitly disconnected by the user.

Chrome OS network performance metric that tracks the number of LinkMonitor broadcast errors that were accrued on an Ethernet network at the time that the link was declaired to be failed.

Chrome OS metric that signals the type of failure the LinkMonitor encountered which caused it to stop monitoring an Ethernet network.

Chrome OS network performance metric that tracks the number of milliseconds between an ARP request and a received reply on an Ethernet network.

Chrome OS network performance metric that tracks the number of seconds from the start of the LinkMonitor until failure on an Ethernet network.

Chrome OS network performance metric that tracks the number of LinkMonitor unicast errors that were accrued on an Ethernet network at the time that the link was declaired to be failed.

Chrome OS network diagnostic metric sampling the number of portal detection attempts per pass for an Ethernet network. This includes failure, timeout and successful attempts.

Chrome OS network diagnostic metric sampling the total number of portal detection attempts performed for an Ethernet network between the Connected and Online state. This includes failure, timeout and successful attempts.

Chrome OS network diagnostic metric sampling the result of portal detections for an Ethernet network.

Chrome OS network performance metric sampling the time to join a wired Ethernet network and configure Layer 3 state (typically acquire a DHCP lease).

Chrome OS network performance metric sampling the time to initialize an Ethernet device.

Chrome OS network performance metric sampling the time to determine that an Ethernet network is online after configuring Layer 3 state.

Chrome OS network performance metric sampling the time to determine that an Ethernet network is in a captive portal after configuring Layer 3 state.

Chrome OS connection manager service errors seen.

Deprecated 10/2012. No longer tracked.

Chrome OS network diagnostic metric sampling the number of termination actions that successfully complete or fail when shill terminates.

Chrome OS network diagnostic metric sampling the number of termination actions that successfully complete or fail when shill suspends.

Chrome OS network diagnostic metric sampling the number of termination actions that successfully complete or fail when shill terminates.

Chrome OS network diagnostic metric sampling the time in milliseconds it takes termination actions to complete when shill suspends.

Chrome OS network diagnostic metric sampling the time in milliseconds it takes termination actions to complete when shill terminates.

Chrome OS network stability metric sampling the time in seconds between the networking going online to going offline. Offline events due to device shutdown or suspend are ignored (along with the online time before that offline event).

Chrome OS network usage metric sampled on each successful VPN connection that tracks the VPN connection type.

Chrome OS network usage metric sampled on each successful VPN connection that tracks the remote authentication method.

Chrome OS network performance metric sampling the time to configure Layer 3 state on a VPN network (typically acquire a DHCP lease).

Chrome OS network performance metric sampling the time to determine that a WiMax network is online after configuring Layer 3 state.

Chrome OS network usage metric sampled on each successful VPN connection that tracks the user authentication method.

Chrome OS network usage metric. Reason code reported when the AP disconnects a wifi connection.

Chrome OS network usage metric. Broad category of reason AP disconnected a WiFi connection.

Chrome OS network usage metric. The channel used for each successful WiFi connection.

Chrome OS network usage metric. Reason code reported when the client disconnects a wifi connection.

Chrome OS network usage metric. Broad category of reason client disconnected a WiFi connection.

Chrome OS network usage metric that tracks whether an 802.11 wireless network was disconnected due to an error or was explicitly disconnected by the user.

Chrome OS network usage metric sampled on each successful 802.1x wireless connection that tracks the configured inner authentication method.

Chrome OS network usage metric sampled on each successful 802.1x wireless connection that tracks the configured outer authentication method.

Chrome OS network diagnostic metric sampling the number of different WiFi frequencies to which the user's machine has ever connected.

Chrome OS network performance metric that tracks the number of LinkMonitor broadcast errors that were accrued on an 802.11 wireiless network at the time that the link was declaired to be failed.

Chrome OS metric that signals the type of failure the LinkMonitor encountered which caused it to stop monitoring an 802.11 wireless network.

Chrome OS network performance metric that tracks the number of milliseconds between an ARP request and a received reply on an 802.11 wireless network.

Chrome OS network performance metric that tracks the number of seconds from the start of the LinkMonitor until failure on an 802.11 wireless network.

Chrome OS network performance metric that tracks the number of LinkMonitor unicast errors that were accrued on an 802.11 wireless network at the time that the link was declaired to be failed.

Chrome OS network usage metric. The channel type used for each successful WiFi connection.

Chrome OS network diagnostic metric sampling the number of portal detection attempts per pass for an 802.11 wireless network. This includes failure, timeout and successful attempts.

Chrome OS network diagnostic metric sampling the total number of portal detection attempts performed for an 802.11 wireless network between the Connected and Online state. This includes failure, timeout and successful attempts.

Chrome OS network diagnostic metric sampling the result of portal detections for an 802.11 wireless network.

Chrome OS network usage metric. The security setting for each successful WiFi connection.

Chrome OS network metric indicating the negative of the dBm received signal strength recorded at the time a successful WiFi connection started.

Chrome OS network metric sampling the time spent using WiFi to transport data. These data are mostly useful when summed and compared to TimeOnline for other network technologies (e.g. WiFi vs Cellular).

Chrome OS network performance metric sampling the time from the resume event to the time when an 802.11 wireless network has configured its Layer 3 state.

Chrome OS network performance metric sampling the time to configure Layer 3 state on an 802.11 wireless network (typically acquire a DHCP lease).

Chrome OS network performance metric sampling the time to initialize an 802.11 wireless device.

Chrome OS network performance metric sampling the time to join (associate plus authenticate) an 802.11 wireless network.

Chrome OS network performance metric sampling the time to determine that an 802.11 wireless network is online after configuring Layer 3 state.

Chrome OS network performance metric sampling the time to determine that an 802.11 wireless network is in a captive portal after configuring Layer 3 state.

Chrome OS network performance metric sampling the time to scan WiFi until a connection is found.

Chrome OS network performance metric sampling the time to configure Layer 3 state on a WiMax network (typically acquire a DHCP lease).

Chrome OS network performance metric sampling the time to initialize a WiMax device.

Chrome OS network performance metric sampling the time to determine that a WiMax network is online after configuring Layer 3 state.

Chrome OS network performance metric sampling the time to join a 3G/Cellular network and configure Layer 3 state. Note this metric is deprecated; see Network.Cellular.TimeToConfig.

Chrome OS network performance metric sampling the time to join a wired Ethernet network and configure Layer 3 state (typically acquire a DHCP lease). Note this metric is deprecated; see Network.Ethernet.TimeToConfig.

Chrome OS network performance metric sampling the time to configure Layer 3 state on an 802.11 wireless network (typically acquire a DHCP lease). Note this metric is deprecated; see Network.Wifi.TimeToConfig.

Chrome OS network performance metric sampling the time to join (associate plus authenticate) an 802.11 wireless network. Note this metric is deprecated; see Network.Wifi.TimeToJoin.

Chrome OS network performance metric sampling the time to configure Layer 3 state on an 802.11 wireless network (typically acquire a DHCP lease).

Network metric reporting the download speed test results run at setup time. Recorded at least once per day.

Chrome OS network usage metric. The channel used for each successful WiFi connection.

Network metric indicating the negative of the dBm noise level recorded at the time the metric is collected. Reported at least once per day and only when the device is idle.

Network metric indicating the negative of the dBm received signal level recorded at the time the metric is collected. Reported at least once per day and only when the device is idle.

Network metric indicating signal minus noise in dBm recorded at the time the metrics is collected. Reported at least once per day and only when the device is idle.

Network metric indicating the negative of the dBm noise level recorded at the time the metric is collected. Reported at least once per day.

Chrome OS network usage metric. The channel type used for each successful WiFi connection.

Network metric reporting the average round trip time to the wifi gateway. Recorded at least once per day.

Chrome OS network usage metric. The security setting for each successful WiFi connection.

Network metric indicating the negative of the dBm received signal level recorded at the time the metric is collected. Reported at least once per day.

Network metric indicating signal minus noise in dBm recorded at the time the metrics is collected. Reported at least once per day.

Chrome OS network performance metric sampling the time from the resume event to the time when an 802.11 wireless network has configured its Layer 3 state.

Chrome OS network performance metric sampling the time to configure Layer 3 state on an 802.11 wireless network (typically acquire a DHCP lease).

Chrome OS network performance metric sampling the time to join (associate plus authenticate) an 802.11 wireless network.

Chrome OS network performance metric sampling the time to determine that an 802.11 wireless network is online after configuring Layer 3 state.

Chrome OS network performance metric sampling the time to determine that an 802.11 wireless network is in a captive portal after configuring Layer 3 state.

Histogram for the source of app page drags. For any succesful drop onto an apps pane of the NTP, this logs where the drag originated.

The default pane when the NTP is first opened.

Histogram of the time, in milliseconds, users have the cursor over a most visited thumbnail before clicking.

Histogram of the time, in milliseconds, users have the cursor over a most visited thumbnail before moving it away from the thumbnail without clicking.

Android: Tallies counts for how the user interacted with the NTP promo page.

Histogram for user clicks of the most visited thumbnails. The value is equal to the index of the thumbnail.

Action taken by the user on the Most Visited NTP pane. If the user switches panes during this use of the NTP, this action is sometimes not recorded. Ask mpearson@ for details.

The number of screenshots that were cached for the non-visible but ranked suggestions on the Suggested NTP pane.

Given that the user has typed a URL, and given that that specific URL was ranked but not visible on the Suggested pane of the NTP, this is the rank that the Suggested pane had for that URL.

Histogram for usage of the menu on the NTP that allows the user to access tabs from other devices.

The pane that had been previously selected when the user switches panes in the NTP.

Histogram for NTP bubble promo activity.

Histogram for NTP notification promo activity.

TBD.

The pane selected when the user switches panes in the NTP.

Histogram for user clicks of the Recently Closed items. The value is the recency of the entry being restored (0 is most recent).

Histogram to track how many times a user switched pages in a single NTP session.

Histogram for user clicks of the suggested site thumbnails. The value is equal to the index of the thumbnail.

Action taken by the user on the Suggested Sites NTP pane.

Time to load the Suggested Sites NTP pane, in milliseconds.

Time spent on the Suggested Sites NTP pane, in seconds.

The number of screenshots that were cached for the visible suggestions on the Suggested NTP pane.

Given that the user has typed a URL, and given that that specific URL was visible on the Suggested pane of the NTP, this is the rank that the Suggested pane had for that URL.

TBD

Deprecated 10/2011. No longer tracked, replaced with NewTabPage.DefaultPageType

The default pane when the NTP is first opened.

Deprecated 10/2011. No longer tracked, replaced with NewTabPage.SelectedPageType

The pane selected when the user switches panes in the NTP.

When a page is loaded in offline mode, the percentage of resources on that page that were successfully loaded.

Aggressive HistoryURL provider field trial deleted in spring 2012.

A number that indicates what omnibox ranking behavior the user is seeing as part of the OmniboxAggressiveHistoryURLProvider field trial (OmniboxAggressiveHistoryURLProvider).

The number of times users enter keyword hint mode "Search ___ for:" and how.

The length of time taken by the named provider"s synchronous pass.

Deprecated 2012-11-14. Replaced by Autocomplete.BookmarkProviderMatchTime.

Time the HistoryContentProvider takes to perform a bookmark search.

Time it takes for the omnibox to become responsive to user input after the user has typed N characters. This measures the time it takes to start all the asynchronous autocomplete providers (but not wait for them to finish).

The id of search engine that was used for search in omnibox. See src/chrome/browser/search_engines/template_url_prepopulate_data.cc for more info.

The time elapsed between the sending of a suggest request to Google until the time the request was returned with status==failed. Ignores requests that were canceled before being returned.

The time elapsed between the sending of a suggest request to Google until the time the request was returned with status==success. Ignores requests that were canceled before being returned.

Counts about the number of suggest requests the omnibox sent, invalidated, and replies received.

Completed overscroll gestures.

An overscroll gesture starts when user scrolls past the edge of the web page and continues scrolling in the same direction. An overscroll gesture is completed when user stops scrolling (e.g. by lifting the fingers from the touchscreen or touchpad).

Navigations that were triggered due to completed overscroll gesture. Note that not all completed overscroll gestures trigger a navigation.

Overscroll gestures initiated by the user. Note that not all overcroll gestures started are completed (e.g. the overscroll gesture is aborted if user clicks or presses a key during the gesture).

Breakdown of how other possible usernames are displayed. Recorded every time we autofill a password form.

The number of times each generated password has been used to log in. Recorded by iterating over stored passwords once per run. This information is persisted and synced.

The number of times each saved password has been used to log in. Does not include generated passwords. Recorded by iterating over stored passwords once per run. This information is persisted and synced.

Chrome OS (ARM Chromebooks using Exynos 5250 only) Adaptive Support Voltage Group, recorded once per bootup. Indicates which "bin" the SoC is part of, which sets the voltage that different rails on the system will run at. The values 0-11 are valid. A value of 12 indicates an error parsing dmesg and should be investigated. See also Platform.LotIdEnum.

Chrome OS number of disk sectors read at boot from kernel start to login-prompt-ready.

Chrome OS number of disk sectors written at boot from kernel start to login-prompt-ready.

Chrome OS size of allocated swap area in megabytes (before compression)

CPU frequency as percent of the baseline frequency, sampled every 30s. This may be throttled down from 100% due to power dissipation issues (too high temperature). It may also be throttled up (turbo), but the kernel does not report the actual turbo frequency, so we put such samples in the 101% bucket.

Peak total (single core) CPU usage for the last sample interval. The sample interval may vary from seconds to several minutes.

Generic event of interest from Chrome OS. Intended mainly to help assess the frequency of rare error conditions.

KB in use in the /cache filesystem tree. Logged once a day.

Chrome OS KB in use in the /home/chronos filesystem tree. Logged once a day during log file cleanup.

KB in use in the /data filesystem tree. Logged once a day.

Chrome OS KB in use in the /var filesystem tree. Logged once a day during log file cleanup.

The maximum supported micro-architecture on an Intel platform. This value is logged at program start time.

The 32-bit hash of a kernel warning. This is the hash of the "file:line" string corresponding to the location of the warning, for instance: "/mnt/host/source/src/third_party/kernel/files/drivers /gpu/drm/i915/intel_dp.c:351" (ignore spurious spaces). The hash is produced by this code: while (*string) hash = (hash << 5) + hash + *string++; Separately each warning is also collected (with its hash) via the crash reporter, but only its first occurrence in each boot session. Contact semenzato@ for further info.

Chrome OS (ARM Chromebooks using Exynos 5250 only) indication about whether we're part of a special lot ID. Special lot IDs are groups of chips that have special case handling in the kernel for the Adaptive Support Voltage code (the normal logic doesn't work). See also Platform.AsvGroup. Note that fused devices are never part of a special lot (currently) and only some unfused lots are "special".

Chrome OS size of active memory as % of total memory.

Chrome OS active anonymous memory (data segments) as % of total memory.

Chrome OS active file-backed memory (executables, ...) as % of total memory.

Chrome OS size of anonymous memory as % of total memory.

Chrome OS size of buffer cache as % of total memory.

Chrome OS: size of file-backed memory minus swap and buffer cache, as % of total memory.

Chrome OS size of inactive memory as % of total memory.

Chrome OS inactive anonymous memory (data segments) as % of total memory.

Chrome OS inactive file-backed memory as % of total memory.

Chrome OS size of mapped memory as % of total memory.

Chrome OS size of free memory as % of total memory.

Chrome OS size of shared memory in Kbytes.

Chrome OS size of slab memory in Kbytes.

Chrome OS amount of swapped-out memory in Kbytes. These, and all other MEMINFO stats, are snapshotted every 30s.

Chrome OS amount of swapped-out memory as % of total RAM. These, and all other MEMINFO stats, are snapshotted every 30s.

Chrome OS unevictable memory (ramfs, SHM_LOCKED, mlocked) in Kbytes.

Peak memory bandwith (read and write) usage during the last sample interval. The sample interval may vary from seconds to several minutes.

Chrome OS total anonymous memory (active + inactive) as % of total memory 1 minute after boot.

Chrome OS total anonymous memory (active + inactive) as % of total memory 5 minutes after boot.

Chrome OS total anonymous memory (active + inactive) as % of total memory 30 minutes after boot.

Chrome OS total anonymous memory (active + inactive) as % of total memory 150 minutes after boot.

Chrome OS total anonymous memory (active + inactive) as % of total memory 750 minutes after boot.

Page faults per second averaged over 30s interval, sampled continuously.

Page faults per second averaged over 1s interval, sampled every 30s.

Number of disk sectors per second read by Chrome OS in a long interval (currently 30s)

Number of disk sectors per second read by Chrome OS in a short interval (currently 1s, sampled every 30s)

Disk communication errors (SMART 199), sent at boot.

Uncorrectable disk errors (SMART 187), sent at boot.

Chrome OS stateful partition usage level.

Peak junction temperature for the last sample interval, read from TSEN on the SoC. The sample interval may vary from seconds to several minutes.

Temperature reading at sensor 0 (I2C_CPU-Die) taken every 30s.

Temperature reading at sensor 1 (I2C_CPU-Object) taken every 30s.

Temperature reading at sensor 2 (I2C_PCH-Die) taken every 30s.

Temperature reading at sensor 3 (I2C_PCH-Object) taken every 30s.

Temperature reading at sensor 4 (I2C_DDR-Die) taken every 30s.

Temperature reading at sensor 5 (I2C_DDR-Object) taken every 30s.

Temperature reading at sensor 6 (Charger-Die), taken every 30s.

Temperature reading at sensor 7 (Charger-Object) taken every 30s.

Temperature reading at sensor 8 (ECInternal) taken every 30s.

Temperature reading at sensor 9 (PECI) taken every 30s.

Each sample is the number of consecutive reboots performed while attempting to clear a TPM (Trusted Platform Module) error.

Number of disk sectors per second written by Chrome OS in a long interval (currently 30s)

Number of disk sectors per second written by Chrome OS in a short interval (currently 1s, sampled every 30s)

Deprecated as of 2013-05, replaced by PlatformFile.UnknownCreateFileErrorsWin in chrome 29.

Errors returned by CreateFile on windows that PlatformFileError doesn't yet support.

Errors returned by CreateFile on POSIX that PlatformFileError doesn't yet support.

Errors returned by CreateFile on Windows that PlatformFileError doesn't yet support.

Distribution of actual finished pages, vs abandoned pages, where we needed to declare a finish time prematurely since the page was being closed (exited).

TBD

PLT.BeginToFinish, but for pages which contained prefetch links.

PLT.BeginToFinish, but for pages which were referred to by pages which contained prefetch links.

TBD

PLT.BeginToFinishDoc, but for pages which contained prefetch links.

PLT.BeginToFinishDoc, but for pages which were referred to by pages which contained prefetch links.

Time from "begin" to "first paint." "Begin"== "request" if user requested, and "start" otherwise. "Request"== time when user requested document. "Start"== time when renderer requested load of document, after any unload of last document. "First paint"== time when first paint operation was performed.

Time from "commit" to "first paint." "Commit"== time when renderer got first byte of document. "First paint"== time when first paint operation was performed.

Probability distribution for enumerated varieties of page loads.

Deprecated as of 5/02/2011, replaced by Prerender.RendererPLT.

Perceived load time of a page. For non-prerendered pages, this is just BeginToFinish. For displayed prerendered pages, this is the time from when the prerendered page is moved into a TabContents until finish. "Finish" == after onload() and all resources are loaded. Note that this is 0 if the loading finishes before the page is moved into a TabContents.

Deprecated as of 5/02/2011, replaced by Prerender.RendererPerceivedPLTMatched.

Perceived load time of a prerendered page that is displayed. This is the time from when the prerendered page is moved into a TabContents until finish. "Finish" == after onload() and all resources are loaded. Note that this is 0 if the loading finishes before the the page is moved into a TabContents.

Time from "request" to "finish." "Request" == time when user requested document. "Finish" == after onload() and all resources are loaded.

Time from "start" to "commit." "Start"== time when renderer requested load of document, after any unload of last document. "Commit"== time when renderer got first byte of document.

Time from "start" to "finish." "Start"== time when renderer requested load of document, after any unload of last document. "Finish"==after onload() and all resources are loaded.

The result from an attempt to load a PPAPI broker.

The result from an attempt to load a PPAPI plugin.

The level of the backlight as a percentage when the user is on AC. Sampled every 30 seconds.

The level of the backlight as a percentage when the user is on battery. Sampled every 30 seconds.

Chrome OS battery charge health percentage. Sampled once when device starts charging.

Chrome OS battery discharge rate in mW sampled every 30 seconds while the device runs on battery.

Chrome OS battery discharge rate in mW while the system was suspended, sampled at resume. Only reported if the system was on battery power both before suspending and after resuming, if the energy level didn't increase while suspended (which would indicate that an AC adapter was connected), and if the system was suspended for at least a minute.

Counts the number of times we have read the battery status from sysfs and if it gave us sensible values.

Chrome OS remaining battery charge as percent of the maximum battery charge, sampled at the end of a user session when the device is on AC.

Chrome OS remaining battery charge as percent of the maximum battery charge, sampled at the end of a user session when the device is on battery.

Chrome OS remaining battery charge as percent of the maximum battery charge, sampled at the start of a user session when the device is on AC.

Chrome OS remaining battery charge as percent of the maximum battery charge, sampled at the start of a user session when the device is on battery.

Deprecated as of 03/2012, no longer being generated by powerd.

Chrome OS remaining battery charge as percent of the maximum battery charge sampled when the device runs on battery.

Chrome OS remaining battery charge as percent of the maximum battery charge, sampled when charging starts.

Deprecated as of 03/2012, no longer being generated by powerd.

Chrome OS remaining time to empty battery in minutes sampled when the device runs on battery.

Chrome OS (Snow RO firmware 2695.90.0 only) number of 8K chunks that were fixed (memory corruption corrected) for each suspend/resume cycle. Expect 0 around 97% of the time and a non-zero value around 3% of the time.

Chrome OS (Snow RO firmware 2695.90.0 only) number of 4-byte words that were fixed (memory corruption corrected) for each suspend/resume cycle. Expect 0 around 97% of the time and a non-zero value around 3% of the time. Would be exactly equal to Power.BitfixChunks if there were only one corrupted word in each chunk but is sometimes several times higher.

Deprecated as of 5/2013. See Accel_BrightnessDown_F6 and Accel_BrightnessUp_F7 user actions instead.

Number of times the user has adjusted brightness up and down while running on battery power.

Deprecated as of 5/2013. See Accel_BrightnessDown_F6 and Accel_BrightnessUp_F7 user actions instead.

Number of times the user has adjusted brightness up and down while running on AC power.

The time that the firmware took to resume the Chrome OS device from suspend-to-RAM state when running on AC at pre-suspend time.

The time that the firmware took to resume the Chrome OS device from suspend-to-RAM state when running on battery at pre-suspend time.

Chrome OS user idle time since the screen dimmed sampled when the user becomes active again if the device runs on AC.

Chrome OS user idle time since the screen dimmed sampled when the user becomes active again if the device runs on battery.

Chrome OS user idle time since the screen turned off sampled when the user becomes active again if the device runs on AC.

Chrome OS user idle time since the screen turned off sampled when the user becomes active again if the device runs on battery.

Chrome OS user idle time sampled when the user becomes active again if the device runs on AC.

Chrome OS user idle time sampled when the user becomes active again if the device runs on battery.

The time that the kernel took to resume the Chrome OS device from suspend-to-RAM state when running on AC at pre-suspend time.

The time that the kernel took to resume the Chrome OS device from suspend-to-RAM state when running on battery at pre-suspend time.

The time that the kernel took to suspend-to-RAM the Chrome OS device when running on AC.

The time that the kernel took to suspend-to-RAM the Chrome OS device when running on battery.

The level of the keyboard backlight as a percentage. Sampled every 30 seconds.

The length of time, in seconds, that a user spent in a single session. Values for this metric are clamped to 12 hours, so the last bucket should be considered to be including all metrics above 12 hours.

The average power consumption, measured in milli-units per hour, when sync invalidator listens to on_application_active events. Values for this metric are per session, i.e. from battery level at application entering foreground to returning to background, and normalized to an hourly average consumption. This is an iOS only measurement. Due to how iOS reports battery levels, it is likely to see many readings of 0.

The average power consumption, measured in milli-units per hour, for other sync invalidator methods. Values for this metric are per session, i.e. from battery level at application entering foreground to returning to background, and normalized to an hourly average consumption. This is an iOS only measurement. Due to how iOS reports battery levels, it is likely to see many readings of 0.

The average power consumption, measured in milli-units per hour, when sync invalidator uses peer-to-peer notifications. Values for this metric are per session, i.e. from battery level at application entering foreground to returning to background, and normalized to an hourly average consumption. This is an iOS only measurement. Due to how iOS reports battery levels, it is likely to see many readings of 0.

The average power consumption, measured in milli-units per hour, when sync invalidator uses server-based non-blocking invalidator. Values for this metric are per session, i.e. from battery level at application entering foreground to returning to background, and normalized to an hourly average consumption. This is an iOS only measurement. Due to how iOS reports battery levels, it is likely to see many readings of 0.

The number of times that the Automatic Light Sensor (ALS) adjusted the brightness during a session. Values for this metric are clamped to 10k count, so the last bucket should be considered to be including all metrics above 10k.

The number of user sessions that occured since the last time that the device was charged. Values for this metric are clamped at 10k, so the last bucket should be considered to include all metrics about 10k.

The number of times Chrome OS retried suspend due to previous failure.

ChromeOS suspend status - either success, failure, or cancelled.

The percentage of aborted fan attempts out of total fan attempts per session, where an abort is due to hysteresis. This value is computed from boot and sent when powerd starts and then every 15 minutes afterwards.

The percentage of fan trip point passes that are more than one trip point. This value is computed from boot and sent when powerd starts and then every 15 minutes afterwards.

Chrome OS time in minutes spent in suspend-to-RAM mode sampled at boot (i.e., the device most likely ran out of battery while in suspend).

Chrome OS time in minutes spent in suspend-to-RAM mode sampled at resume.

The number of times that the user adjusted the brightness during a session when on AC. Values for this metric are clamped to 10k count, so the last bucket should be considered to be including all metrics above 10k.

The number of times that the user adjusted the brightness during a session when on battery. Values for this metric are clamped to 10k count, so the last bucket should be considered to be including all metrics above 10k.

deprecated May 10 2012

Hover Event counts for prerendering.

Final status for prerender pages - either success, or why it was canceled.

Final status for prerender pages - either success, or why it was canceled. This is for the MatchComplete set of pages (including some pages that were not actually prerendered), to match the control group.

For prerenders that are swapped in, the percentage of pixels that is already final at swap-in time compared to when the spinner stops.

deprecated May 10 2012

Duration that a user hovers a link before clicking on it. This is recorded for all pages loaded in a session.

deprecated May 10 2012

Duration that the mouse pointer hovers on a link before the mouse pointer moves off of it. This is recorded for all pages loaded in a session.

Enumeration of what events related to the local predictor have occurred

Time from when a prerendered page is started to when it is first used due to user navigation. If the page is never used, it is not included in this histogram. This only refers to prerenders based on the local predictor.

deprecated Nov 16 2012

The transition type for each new visit as recorded in the local visits database.

deprecated Nov 16 2012

Size of the local visits database (number of entries).

deprecated Nov 16 2012

Enumeration of what events related to local visits have occurred

A boolean that indicates whether the Omnibox navigation being committed could have been prerendered by the Omnibox Prerender system. This provides an upper bound for Prerender.OmniboxNavigationsUsedPrerenderCount and allows the potential for Omnibox Prerendering coverage to be understood. If Omnibox Prerendering is disabled, this histogram will register a 'false' entry. The total count is the equivalent of the deprecated NetworkActionPredictor.NavigationCount histogram.

The number of navigations that use a prerender initiated from the Omnibox. The count is incremented when the Prerendered tab is swapped in if the Prerender was initiated by the Omnibox, which obviously requires Prerendering from the Omnibox to be enabled.

The number of prerenders initiated from the Omnibox. This is incremented when the NetworkActionPredictor suggests Prerendering as an optimal strategy given the text the user has entered and the Autocomplete suggestion currently selected. It is only incremented if Prerendering from the Omnibox is enabled.

deprecated Nov 16 2012

Types of pages rendered.

Deprecated 03/24/11. Replaced by Prerender.PerceivedPLT_ContentPrefetchPrerenderControl.

Deprecated 03/24/11. Replaced by Prerender.PerceivedPLTMatched_ContentPrefetchPrerenderControl.

Deprecated 03/24/11. Replaced by Prerender.PerceivedPLTMatched_ContentPrefetchPrerender.

Deprecated 03/24/11. Replaced by Prerender.PerceivedPLT_ContentPrefetchPrerender.

Deprecated 03/24/11. Replaced by Prerender.PerceivedPLTWindowed_ContentPrefetchPrerenderControl.

Time from when a user navigates to a page to when it loads. Since the pages may start loading before the user navigates to it, this does not include any portion of load prior to navigation. This particular histogram is for all page loads within 30 seconds after a prefetch tag is seen for users who do not have prerendering enabled.

Deprecated 03/24/11. Replaced by Prerender.PerceivedPLTWindowed_ContentPrefetchPrerender.

Time from when a user navigates to a page to when it loads. Since the pages may start loading before the user navigates to it, this does not include any portion of load pre navigation. This particular histogram is for all page loads within 30 seconds after a prefetch tag is seen for users who have prerendering enabled.

Time from when a user navigates to a page to when it loads. Since the pages may start loading before the user navigates to it, this does not include any portion of load prior to navigation. "FirstAfterMiss" means the first pageload after a prerender miss. There are two types: Any, and Non-overlapping. The latter only applies to page loads initiated after the prerender. This variable records cases where only Any triggered.

Time from when a user navigates to a page to when it loads. Since the pages may start loading before the user navigates to it, this does not include any portion of load prior to navigation. "FirstAfterMiss" means the first pageload after a prerender miss. There are two types: Any, and Non-overlapping. The latter only applies to page loads initiated after the prerender. This variable records cases where both triggered.

Time from when a user navigates to a page to when it loads. Since the pages may start loading before the user navigates to it, this does not include any portion of load prior to navigation. This is recorded for the first page load completing immediately after a prerender, but which has also started after the prerender has been initiated.

Time from when a user navigates to a page to when it loads. Since the pages may start loading before the user navigates to it, this does not include any portion of load prior to navigation. "FirstAfterMiss" means the first pageload after a prerender miss. There are two types: Any, and Non-overlapping. The latter only applies to page loads initiated after the prerender. This variable records cases where only Non-overlapping triggered.

Time from when a user navigates to a page to when it loads. Since the pages may start loading before the user navigates to it, this does not include any portion of load prior to navigation. This is recorded only for prerendered pages, or for pages which would have been prerendered in the control case. In MatchedComplete, the prerender group also contains cancelled prerenders, so as to produce a perfect match of page views attributed this group in the prerender group with those attributed to this group in the control group.

Time from when a user navigates to a page to when it loads. Since the pages may start loading before the user navigates to it, this does not include any portion of load prior to navigation. This is recorded for all page loads which happen within 30 seconds after a prefetch tag is observed and which do not correspond to a prerender tag.

For prerenders that are swapped in, the percentage of the time from load start until the onload event fires that has elapsed at the time of the swapin.

After launching a prerender, how many simultanious prerenders are recorded as running, out of a maximum of three.

For prerenders that finish loading before they are ever swapped in, their page load time until the onload event fires.

The number of sessions that have at least X successful prerenders.

deprecated Nov 16 2012

This is the time from when a prerendered page finishes loading to when it is displayed, as measured by the renderer process. When a page is displayed before it finishes loading, no value is recorded in this histogram.

deprecated Nov 16 2012

Perceived load time of a page, as measured by the renderer process. For non-prerendered pages, this is just BeginToFinish. For displayed prerendered pages, this is the time from when the prerendered page is moved into a TabContents until finish. "Finish" == after onload() and all resources are loaded. Note that this is 0 if the loading finishes before the page is moved into a TabContents.

deprecated Nov 16 2012

Perceived load time of a prerendered page that is displayed, as measured by the renderer process. This is the time from when the prerendered page is moved into a TabContents until finish. "Finish" == after onload() and all resources are loaded. Note that this is 0 if the loading finishes before the the page is moved into a TabContents.

deprecated Nov 16 2012

The time elapsed between when the prerendering of a page starts and when the page is displayed, as measured by the renderer process. Prerendered pages discarded without being displayed are excluded from this count.

The detailed reason why a prerender is canceled with FINAL_STATUS_UNSUPPORTED_SCHEME

deprecated Nov 16 2012

Enumeration of how prerender was used per session.

For simulated local browsing prerendering, the baseline PLT of pages without any prerendering for pages that would be prerendered.

For simulated local browsing prerendering, the estimated PLT of pages with prerendering enabled for pages that would be prerendered.

A boolean that indicates how often we fail to delete an old prerendered tab before the timeout.

Enumeration of what events related to the TabHelper class have occurred.

Time between subsequent prerender requests.

The time elapsed between the most recent visit to a URL and when an attempted prerender of the same URL is cancelled with FINAL_STATUS_RECENTLY_VISITED.

deprecated Nov 16 2012

Duration that a user hovers a link before clicking on it.

deprecated Nov 16 2012. See Prerender.TimeUntilUsed2, which has a larger range.

Time from when a prerendered page is started to when it is first used due to user navigation. If the page is never used, it is not included in this histogram.

The number of installed apps when a profile is opened.

Result (final status) when creating a new profile.

Back-end time elapsed while creating a new profile.

Time elapsed before the user decided to cancel creation of a new profile. Since only managed-user profile creation can be canceled, this time comes from managed-user registration.

The time it takes for the compositor to draw a frame.

The amount by which the compositor's draw duration was overestimated in a particular frame (0 if the duration was perfectly predicted or underestimated).

The amount by which the compositor's draw duration was underestimated in a particular frame (0 if the duration was perfectly predicted or overestimated).

A lower-bound on the percentage increase in memory that would result from promoting all layers that have a webkit-transition on opacity or transform.

The time from when a document finished loading to when all it's resources are also loaded.

Deprecated 6/15/09. Replaced by Renderer2.RequestToFinish_L

The time from when a page was requested by a user to when it is fully loaded.

The time from when a page was requested by a user to its first layout.

The time from when a page was requested by a user to when it starts loading.

The time from when a page started loading to when it is fully loaded.

The time from when a page starts loading to when the main document is finished loading.

The time from when a page starts loading to its first layout.

Distribution of actual finished pages, vs abandoned pages, where we needed to declare a finish time prematurely since the page was being closed (exited).

Time spent by WebKit painting the page, in milliseconds, when the GPU acceleration is active, for paints that affect non-root layers.

WebKit paint throughput, measured in megapixels per second, when GPU acceleration is active, for paints that affect non-root layers.

Time between frames when GPU acceleration is active.

Time spent by WebKit painting the page, in milliseconds, when the GPU acceleration is active, for paints that affect the root layer.

WebKit paint throughput, measured in megapixels per second, when GPU acceleration is active, for paints that affect the root layer.

Time from when the animation callback was posted to when it ran.

Time from "begin" to "commit." "Begin"== "request" if user requested, and "start" otherwise. "Request"== time when user requested document. "Start"== time when renderer requested load of document, after any unload of last document. "Commit"== time when renderer got first byte of document.

TBD

Time from "big" to "first paint after load." "Begin"== "request" if user requested, and "start" otherwise. "Request"== time when user requested document. "Start"== time when renderer requested load of document, after any unload of last document. "First paint after load"== time after onload() when first paint operation is performed.

Time from "commit" to "finish." "Commit"== time when renderer got first byte of document. "Finish"==after onload() and all resources are loaded.

Time from "commit" to "finish doc." "Commit"== time when renderer got first byte of document. "Finish doc" == main document loaded, before onload(). "Finish"==after onload() and all resources are loaded.

Time from "commit" to "first paint." "Commit"== time when renderer got first byte of document. "First paint"== time when first paint operation was performed.

Time from "commit" to "first paint after load." "Commit"== time when renderer got first byte of document. "First paint after load"== time after onload() when first paint operation is performed.

Time between frames, as measured on the compositor thread. This is collected once per frame while it is being drawn to the screen in the compositor.

Renamed to Renderer4.pixelCountCulled_Draw.

Number of pixels that culling prevented being drawn to the screen, normalized to the viewport size. This is collected once per frame while it is being drawn to the screen in the compositor.

Renamed to Renderer4.pixelCountOpaque_Draw.

Number of pixels drawn to the screen and known opaque, normalized to the viewport size. This is collected once per frame while it is being drawn to the screen in the compositor.

Renamed to Renderer4.pixelCountTranslucent_Draw.

Number of pixels drawn to the screen and not known opaque, normalized to the viewport size. This is collected once per frame while it is being drawn to the screen in the compositor.

Time from "finish doc" to "finish." "Finish doc"== main document loaded, before onload(). "Finish"==after onload() and all resources are loaded.

Time from "finish " to "first paint after load." "Finish"==after onload() and all resources are loaded. "First paint after load"== time after onload() when first paint operation is performed.

Time to determine the page language. This is done after the page has been loaded.

The ratio of LCDText CC Layers / candidate LCDText layers. Recorded in LayerTreeHost, after LayerTreeHostCommon::CalculateDrawProperties() has computed the properties we need. Only recorded for the first 50 frames of every page.

The ratio of CC Layers which are candidates for LCDText AA / total picture or content Layers. Recorded in LayerTreeHost, after LayerTreeHostCommon::CalculateDrawProperties() has computed the properties we need. Only recorded for the first 50 frames of every page.

Probability distribution for enumerated varieties of page loads.

Number of pixels that culling prevented being drawn to the screen, recorded as 10 times the percentage of the viewport that these pixels cover. This is collected once per frame while it is being drawn to the screen in the compositor.

Number of pixels known to be opaque, recorded as 10 times the percentage of the viewport that these pixels cover.

Number of pixels painted by WebKit into main memory, recorded as 10 times the percentage of the viewport that these pixels cover. This is collected once per commit from WebKit to the compositor.

Number of pixels not known to be opaque opaque, recorded as 10 times the percentage of the viewport that these pixels cover.

The number of render passes (or render targets) in the renderer's frame. If the value is more than one, then an intermediate rendering target must be used during the rendering of the frame for each render pass greater than one.

Time from "request" to "finish." "Request"== time when user requested document. "Finish"==after onload() and all resources are loaded.

Time from "request" to "start." "Request"== time when user requested document. "Start"== time when renderer requested load of document, after any unload of last document.

Time to capture a renderer snapshot.

Time between frames when the page is not GPU accelerated.

Time spent by WebKit painting the page, in milliseconds, when the page is not GPU accelerated.

WebKit paint throughput, measured in megapixels per second, when the page is not GPU accelerated.

Time from "start" to "commit." "Start"== time when renderer requested load of document, after any unload of last document. "Commit"== time when renderer got first byte of document.

Time from "start" to "finish." "Start"== time when renderer requested load of document, after any unload of last document. "Finish"==after onload() and all resources are loaded.

The number of microseconds it took to upload a tile's full texture as measured on the GPU process.

Time to capture a renderer thumbnail.

Number of tiles that culling prevented being uploaded to texture memory. This is an approximation and is recorded as a 100 times the percentage of the number of tiles, of default size, needed to cover the viewport. This is collected once per commit from WebKit to the compositor.

Deprecated as of 04/2012, replaced with Renderer4.tileCountCulled_Upload.

Number of pixels that culling prevented being uploaded to texture memory, normalized to the viewport size. This is collected once per commit from WebKit to the compositor.

Renamed to Renderer4.pixelCountOpaque_Upload.

Number of pixels uploaded to texture memory and known to be opaque, normalized to the viewport size. This is collected once per commit from WebKit to the compositor.

Renamed to Renderer4.pixelCountTranslucent_Upload.

Number of pixels uploaded to texture memory and not known opaque, normalized to the viewport size. This is collected once per commit from WebKit to the compositor.

The state of the requestAutocomplete() dialog when it was dismissed.

The initial state of a user that's interacting with a freshly shown requestAutocomplete() dialog.

User interactions with the Autofill popup shown while filling an requestAutocomplete() dialog.

Measures the frequency of security warnings and errors in the RequestAutocomplete dialog.

Measures the duration for which an requestAutocomplete() dialog was shown.

Measures the duration for which an requestAutocomplete() dialog was shown, in cases where the user ended up canceling out of the dialog.

Measures the duration for which an requestAutocomplete() dialog was shown, in cases where the user ended up accepting the dialog.

Measures how users are interacting with the requestAutocomplete() dialog UI.

Measures the duration of time it takes for the requestAutocomplete() UI to be actionable by the user after it is shown.

Measures the frequency of errors in communicating with the Google Online Wallet server.

Measures the frequency of required user actions returned by the Google Online Wallet server.

The first stage check that measures the time that Chrome took to check if a URL is present in our in-memory bloom filter.

Deprecated 9/2012. No longer generated.

TBD.

The second stage check that measures the time that Chrome took to check if a URL is present in our SQLite database.

The second stage check that mesures the time that Chrome took to check if a URL is present in our SQLite database. This time includes the filter check time.

This measures the time that SafeBrowsing actually delayed the browsing experience. It records the difference between the time when Chrome would have started reading the response for a URL and when the SafeBrowsing system completed its check of that URL.

The first stage check that measures the time that Chrome took to check if a URL is present in our in-memory hash table.

The third and final stage check that mesures the time that Chrome took to get a response from the Google SafeBrowsing servers for a particular URL.

The third and final stage check that mesures the time that Chrome took to get a response from the Google SafeBrowsing servers for a particular URL. This time includes the filter and database check time.

TBD.

The number of add prefixes stored in the database after the last update.

Track failures when in processing the safe-browsing database bloom filter.

All prefix misses (server returned no full hashes) and prefix misses due to false positives in the bloom filter.

Time to load the BloomFilter file.

The size of the browsing SafeBrowsing database file on disk in kilobytes, after an update has occurred.

The time that it took to regenerate the filter after we have received all the update chunks.

Deprecated because it was exceeding the range. Replaced by SB2.BuildReadKilobytes.

The number of bytes read by the browser process during the bloom filter generation phase.

The number of kilobytes read by the browser process during the filter generation phase.

The number of read operations issued by the browser process during the filter generation phase.

Deprecated because it was exceeding the range. Replaced by SB2.BuildWriteKilobytes.

The number of bytes written by the browser process during the bloom filter generation phase.

The number of kilobytes written by the browser process during the filter generation phase.

The number of write operations issued by the browser process during the filter generation phase.

The time that it takes to write one redirect URL (which can contain multiple chunks) to the database.

The network time between the request and response for a chunk.

The size of one chunk URL.

Deprecated because it was exceeding the range. Replaced by SB2.DatabaseKilobytes.

The size of the SafeBrowsing database file on disk.

Track failures when updating the safe-browsing database.

Replaced by SB2.BrowseDatabaseKilobytes.

The size of the SafeBrowsing database file on disk in kilobytes.

The time it takes to initialize the SafeBrowsing storage backend, in milliseconds.

The size of the update file before merging with the database file, in kilobytes.

The time that SafeBrowsing actually delayed the browsing experience. It records the difference between the time when Chrome would have started reading the response for a URL and when the SafeBrowsing system completed its check of that URL.

Records results of SafeBrowsing download check, including both url check and downloaded file hash check.

The size of the downloads SafeBrowsing database file on disk in kilobytes, after an update has occurred.

The time it takes for a download to finish.

The time it takes for SafeBrowsing to check hash of a download file.

The time it takes for SafeBrowsing to check a download url.

Deprecated 3/11/11, and replaced by SB2.DownloadChecks.

Records results of SafeBrowsing download url check.

Deprecated, replaced by SB2.DatabaseFailure BROWSE_DB_UPDATE_FINISH.

The count of the number of times an update failed when being committed to the database.

The time that it took to check a URL against our in-memory filter.

Deprecated 9/2012. No longer generated.

The size of the current bloom filter in kilobytes.

Which filter file the database loaded from disk.

Deprecated, replaced by SB2.DatabaseFailure FILTER_MISSING.

The count of the number of times we attempted to load the bloom filter file but it was missing.

Deprecated, replaced by SB2.DatabaseFailure FILTER_READ.

The count of the number of times we attempted to load the bloom filter file but failed while reading the file on disk.

Deprecated because it was exceeding the range. Replaced by SB2.FilterKilobytes.

The size of the current bloom filter.

Deprecated, replaced by SB2.DatabaseFailure FILTER_WRITE.

The count of the number of times we attempted to save the bloom filter file but failed while writing the file to disk.

Tracks events involved in upgrading safe-browsing data from SQLite format to new file format.

Deprecated in favor of SB2.GetHashResult STATUS_200.

The number of GetHash requests that returned data (valid requests).

Deprecated in favor of SB2.GetHashResult STATUS_204.

The number of GetHash requests that returned empty data (false positives).

Track return status from GetHash requests to server (STATUS_200 and STATUS_204), and dispensation of returned values (EMPTY, HIT, MISS). EMPTY means the response had no full hashes, and should contain all of the 204 responses plus those 200 responses corrosponding to items deleted on the server but not yet deleted on the client. HIT means that one of the full hashes matched. MISS means that none of the hashes matched (there was a prefix collision).

Deprecated in favor of SB2.GetHashResult FULL_HASH_* and SB2.BloomFilterFalsePositives. It is unclear if this histogram ever reported useful data.

The number of GetHash requests returning full hashes that didn't match the URL that initiated the request.

Deprecated, replaced by SB2.DatabaseFailure CORRUPT.

The count of the number of times a database was found corrupt and reset.

Track number of times Safe Browsing interstitials have been shown, and how many times they have been clicked through or not.

The time between when we show the SafeBrowsing malware interstitial and the user navigating away by for example, closing the tab, clicking the browser back button or typing another URL in the address bar.

The time between when we show the SafeBrowsing malware interstitial and the user clicking on diagnostic page link.

The time between when we show the SafeBrowsing malware interstitial and the user expanding the "see more info" section of the page. (Only applies to field trial version 2 of the interstitial.)

The time between when we show the SafeBrowsing malware interstitial and the user clicking on the learn more about malware link.

The time between when we show the SafeBrowsing malware interstitial and the user clicking on the privacy policy link.

The time between when we show the SafeBrowsing malware interstitial and the user clicking on the proceed link.

The time between when we show the SafeBrowsing malware interstitial and the user clicking on the big green back button.

The time that it took to receive a response from the Google SafeBrowsing servers for a GetHash request.

Size of v1 database deleted from client profile.

The time between when we show the SafeBrowsing phishing interstitial and the user navigating away by for example, closing the tab, clicking the browser back button or typing another URL in the address bar.

The time between when we show the SafeBrowsing phishing interstitial and the user expanding the "see more info" section of the page. (Only applies to field trial version 2 of the interstitial.)

The time between when we show the SafeBrowsing phishing interstitial and the user clicking on the learn more link.

The time between when we show the SafeBrowsing phishing interstitial and the user clicking on the proceed link.

The time between when we show the SafeBrowsing phishing interstitial and the user clicking on the report error link.

The time between when we show the SafeBrowsing phishing interstitial and the user clicking on the big green back button.

The size of the PrefixSet storage in bits, divided by the number of prefixes represented. Should almost always be 16.

Deprecated 9/2012. No longer generated, BloomFilter being removed.

Records how well the PrefixSet implementation matches the BloomFilter implementation.

The size of the PrefixSet file in kilobytes.

Time to load the PrefixSet file.

Deprecated 9/2012. No longer generated.

For debugging PrefixSet. How many extra results GetPrefixes returns.

Deprecated 9/2012. No longer generated.

For debugging PrefixSet. How many fewer results GetPrefixes returns.

Deprecated 9/2012. No longer generated.

For debugging PrefixSet. How far unsorted deltas are from expected value.

Deprecated 9/2012. No longer generated.

For debugging PrefixSet. Distance of unsorted elements from expected location.

Deprecated 9/2012. No longer generated.

For debugging PrefixSet. How far into the results unsorted elements were found. Interesting values would be 0%, 50%, or 100%.

Deprecated 9/2012. No longer generated.

For debugging PrefixSet. Size of unsorted sets. To see if there is a problem with a particular size of dataset.

Time to store the PrefixSet file.

The size of the Side Effect Free Whitelist SaafeBrowsing database file on disk in kilobytes, after an update has occurred.

The size of the Side Effect Free Whitelist PrefixSet file in kilobytes, after an udpate has occurred.

Time to load the Side Effect Free Whitelist PrefixSet file.

Time to store the Side Effect Free Whitelist PrefixSet file.

The instantiation status of the SideEffectFreeWhitelist.

The number of sub prefixes stored in the database after the last update.

The time from the receipt of the update request to the receipt of the final update chunk.

The payload size of update requests to the server.

Result from trying to update the SafeBrowsing data.

The size of all the chunk URLs in an update response.

The number of chunk URLs in an update response.

Records a histogram of the reason why downloads are marked as being malicious or clean by the improved SafeBrowsing binary download protection.

Records a histogram of how often users download a file with a file extension that is possibly dangerous (e.g., exe, class).

Records the total time it takes for the SafeBrowsing download service to check whether the content of a download is malicious or not. This histogram only includes requests that are sent to the SafeBrowsing server.

Records the number of signed vs. unsigned executables that are downloaded.

Counter which is incremented whenever an executable is downloaded which is either signed or whose URL matches the download whitelist.

Measures the success rate of sending malware reports. Sending a report can fail due to a client reaching the limit on the number of reports it can send per day or due to the report failing to be serialized.

The counts for various reasons why an in-progress phishing classification was canceled.

The number of times client-side phishing classifier expected to have no pending classifications running but that check failed.

The number of pages that we could have possibly classified (essentially the number of top page navigations by users with SBClientPhishing enabled). The name is slightly misleading as it is recorded before "Preclassification" happens.

The counts for various model status codes that we get after loading a new client-side phishing model.

The time that an individual chunk of DOM feature extraction work took.

The number of times that DOM feature extraction finished early because the active WebDocument's frame was removed during traversal.

The number of iterations that the DOM feature extractor took to finish.

The time that it took to resume DOM feature extraction for the phishing classifier. Longer times may indicate that the page DOM changed between chunks of work and the extractor had to re-traverse up to the saved position.

The number of phishing classifications that were aborted because DOM feature extraction took too long.

The time that the DOM feature extarctor took to finish, summed across all chunks of work.

Time spent generating the thumbnail.

The number of features which were omitted from phishing classification because they were added with an illegal value. This would indicate a bug.

The number of times that the phishing detection service could not be initialized due to an error parsing the private IP networks. This would indicate a bug.

Deprecated 12/2011. Whitelist entries are no longer part of ClientPhishingResponse.

The number of whitelist_expression entries in a ClientPhishingResponse that could not be canonicalized.

Records the number of phishing classifications that were skipped because a pre-classification check failed.

The number of phishing classifications that were previously cached as being phishing but that will get re-classified (to possibly fix false positives).

The number of phishing classifier pingbacks that were skipped because serializing the request protocol buffer to string failed.

The number of times that a cached phishing classification result was used, rather than pinging the server.

Records the status when we create a scorer object for the client-side phishing detection classifier.

The number of phishing classifications that were aborted because the term feature extractor failed to initialize an ICU break iterator.

The time that an individual chunk of term feature extraction work took.

The number of iterations that the term feature extractor took to finish.

The number of phishing classification that were aborted because term feature extraction took too long.

The time that the term feature extarctor took to finish, summed across all chunks of work.

The number of times that the limit on the number of phishing classifier features for a page was reached. This may indicate a bug, or that kMaxFeatureSize is too small.

The time taken to extract URL features for the phishing classifier.

Count of times download feedback has been started, broken down by danger type.

When a new download feedback request is added, records the number of download requests currently active and/or pending.

Count of times download feedback button has been shown, broken down by danger type.

Size of downloads that were of the correct danger type, regardless if they meet the max file size check or if they are actually uploaded or not.

Size of downloads that failed to be uploaded to the feedback service.

Size of downloads that were successfully uploaded to the feedback service.

Final result of attempt to upload binary to download feedback service.

The id of the default search engine that is loaded after Chrome startup. See src/chrome/browser/search_engines/prepopulate_engines.json for more info.

Whether or not the CRC was checked at the moment when the last reference to a read-only entry stream is closed.

The time from the creation of the simple cache backend until the index has been loaded from disk.

The time from the creation of the simple cache backend until the index fails to load.

For entry creation operations that were sent to the disk, the result of creation.

The time, in ms, spent creating a new entry on disk.

At the time that operations are run, the number of pending operations on a particular entry.

The size of the cache at the beginning of an eviction.

The number of entries to be erased in an eviction.

The maximum allowed size of the cache at the beginning of an eviction.

The result of an eviction.

The number of bytes to be erased in an eviction.

The amount of memory freed in an eviction.

The size of the cache after running an eviction.

Time spent completing an eviction.

Time spent selecting entries for eviction.

For each index load, whether the index file was corrupt.

The number of entries in a newly created index file.

Number of entries loaded from the index file on start.

Number of entries restored from disk when there was no index or the index was corrupted.

At the time of index initialization, the number of enqueued jobs awaiting index initialization.

The method used to initialize the simple cache index.

Time (as measured on the worker pool) spent loading the index file.

The number of entries written to the index on a flush.

Time (as measured on the worker pool) spent restoring the index file by iterating directory entries.

For each index load, whether the index file was stale.

The interval between index saves, for apps in the background.

The interval between index saves, for apps in the foreground.

Deprecated 2013-05 in favour of SimpleCache.SimpleIndexWriteToDiskTime.Background and SimpleCache.SimpleIndexWriteToDiskTime.Foreground.

The amount of time spend writing the index file to disk, measured starting at the beginning of the write on the callback thread, and calculated using the completion time on the worker pool.

The amount of time spend writing the index file to disk, for apps in the background, measured starting at the beginning of the write on the callback thread, and calculated using the completion time on the worker pool.

The amount of time spend writing the index file to disk, for apps in the foreground, measured starting at the beginning of the write on the callback thread, and calculated using the completion time on the worker pool.

At the time that an entry is opened, the state of that entry in the index.

The outcome of Entry::ReadData in the simple cache.

For each EOFRecord found with a valid magic number, indicates if the record also contains a CRC.

The result, at the synchronous layer, of checking the EOF record of a cache entry.

The result, at the synchronous layer, of closing a cache entry.

The platform error of attempting to create a new cache entry.

The result, at the synchronous layer, of attempting to create a new cache entry.

The platform error of attempting to create a new cache entry.

The result, at the synchronous layer, of attempting to open a new cache entry.

The result, at the synchronous layer, of writing to a cache entry.

The outcome of Entry::WriteData in the simple cache.

The count of all current BrowsingInstances. Recorded once per UMA ping.

The count of all renderer processes, including WebUI and extensions. Recorded once per UMA ping.

The upper bound of the predicted renderer process count if we isolated all sites, subject to the process limit. Recorded once per UMA ping.

The lower bound of the predicted renderer process count if we isolated all sites, subject to the process limit. Happens to be the number of unique sites. Recorded once per UMA ping.

The predicted renderer process count if we isolated all sites and if there were no process limit. Recorded once per UMA ping.

The predicted total process count if we isolated all sites, subject to the process limit. Recorded once per UMA ping.

The upper bound of the predicted renderer process count if we isolated only HTTPS (not HTTP) sites, subject to the process limit. Recorded once per UMA ping.

The lower bound of the predicted renderer process count if we isolated only HTTPS (not HTTP) sites, subject to the process limit. Happens to be the number of isolated sites. Recorded once per UMA ping.

The predicted renderer process count if we isolated only HTTPS (not HTTP) sites and if there were no process limit. Recorded once per UMA ping.

The predicted total process count if we isolated only HTTPS (not HTTP) sites, subject to the process limit. Recorded once per UMA ping.

Error codes returned by sqlite for the appcache db.

Error codes returned by sqlite the cookie db.

Error codes returned by sqlite the websqldb tracker db.

Error codes returned by sqlite for the domain-bound certs db.

Error codes returned by sqlite for the domstorage db.

SQLite extended error codes.

Replaced 5/14/2013 by expanded Sqlite.Error histogram.

SQLite extended SQLITE_IOERR codes for all databases.

Error codes returned by sqlite for the history db.

Error codes returned by sqlite for the quota db.

Size in kilobytes of pre-existing database at startup.

Error codes returned by sqlite the full text db.

Error codes returned by sqlite for the thumbnail db.

Version of pre-existing database at startup.

Error codes returned by sqlite the web db.

Age of all auth tokens rejected by the invalidation server. Measured from the time they were created.

Age of auth tokens younger than one hour that were rejected by the invalidation server. Measured from the time they were created.

Age of all auth tokens rejected by the sync server. Measured from the time they were created.

Age of auth tokens younger than one hour that were rejected by the sync server. Measured from the time they were created.

Whether OAuth2 refresh token was available at the time when ProfileSyncService was starting backend.

When the browser restores a tab, whether the load was successful. Loads can fail for instance when there is no connectivity.

Load time for a successful tab restore.

When the browser restores a tab, whether the user waits for completion of the load or if the user gives up by switching to another tab or leaving Chrome.

The status of a tab collected each time the tab is displayed on Android, including user switching to the tab and displays of newly created tabs, such as NTP or tabs opened to handle intents.

The status of a tab collected each time the user switches to it on Android. That does not include tabs being created at the time the user switches to them, such as NTP or tabs opened to handle intents.

Age (in ms) when the tab was switched to foreground.

Each time a tab is brought to the foreground, this histogram indicates if chrome was launched without an URL (i.e., from the launcher), or with an URL (i.e., from another app).

Rank in MRU order (0 being first) when the tab was switched to foreground.

Count of all tabs when a tab is switched.

Each time a tab is brought to the foreground, this histogram indicates if this is the first viewing of the tab since Chrome was put into foreground, or if it was a return to a tab that has already been shown in this session.

Tracks touchpad device state.

Tracks unusual CrOS touchpad operational states (e.g. running into the noisy ground issue). This is sampled at every touchpad event.

Tracks touchpad natural scroll setting changes by the user.

Tracks touchpad natural scroll setting on startup.

Tracks touchpad sensitivity setting changes by the user.

Tracks touchpad sensitivity setting on startup.

Tracks touchpad TapDragging setting changes by the user.

Tracks touchpad TapDragging setting on startup.

Tracks touchpad TapToClick setting changes by the user.

Tracks touchpad TapToClick setting on startup.

Tracks touchpad ThreeFingerSwipe setting changes by the user.

Tracks touchpad ThreeFingerSwipe setting on startup.

The number of times the always translate option was selected in the translate infobar.

The time spent capturing plain text from the DOM. This is reported by ChromeRenderViewObserver when a page is loaded completely.

A page may provide a Content-Language HTTP header or a META tag. For each page load, measures whether the Content-Language header exists and is valid.

The number of times the "Nope" (don't translate) was clicked in the translate infobar.

The number of times the translate infobar was closed without the user translating the page.

A page may provide a lang attribute in html tag. For each page load, measures whether the lang attribute exists and is valid.

The reason why Chrome decided to perform the next action (e.g., to show infobar, to translate a page without any prompting, and so on) when Chrome Translate is ready to translate a page.

For each page load, measures whether the provided Content-Language header matches the language determined by CLD. Beyond directly matching or mismatching the Content-Language header, CLD can complement the Content-Language. For example, suppose the Content-Language header specifies 'zh' (general Chinese), a language code that the Translate server does not support. In this case, CLD can detect a subcode like '-TW' or '-CN', resulting in language codes 'zh-TW' and 'zh-CN', which the Translate server supports. This is referred to as "complementing a language subcode".

Logs the user locale when the Translate feature is disabled by the user. This is recorded each time a webpage is loaded and prefs for translation is checked. This allows us to investigate the correlation between the user locale and the usage rates of the Translate.

The number of times the original language in the translate infobar has been changed.

The number of times the target language in the translate infobar has been changed.

The number of times the never translate option was selected in the translate infobar.

The number of times the never translate site was selected in the translate infobar.

Counts translation target page schemes.

The number of times the "report this error" of options menu is selected in the translate infobar.

The number of times the show original button was clicked in the translate infobar.

Deprecated 5/2013 by Translate.UndisplayableLanguage

The number of times the detected language is not supported by Translate Element.

Deprecated 7/2010. No longer tracked.

The number of times an infobar proposing to translate a page has been shown.

Chrome Translate shows an error infobar when an error happens on translation and the infobar message depends on what kind of error happens. This metric counts how often each error message is shown.

This metrics is logged whenever a page is loaded. The logged value is "Mathced" when the CLD-detected language differs from the page language code , and the two languages are such similar languages. In that case, Chrome ignore the CLD-determined language and instead uses the page language code. The page language code is decided by Content-Language and HTML lang attribute.

The time from injecting scripts for Chrome Translate to being ready to perform translation.

The time from injecting scripts for Chrome Translate to the finishing loads of all depending libraries.

The time from starting translation to the completion.

The number of times the translate button was clicked in the translate infobar.

Logs an undisplayable language included in the language list sent by the Translate server. The Translate server sends the list each time the user runs Chrome. This metrics tells us that there is a language which UI should support but doesn't.

Logs an unsupported source language detected during initiation of the Translate feature. This is reported when the language detector successfully detects the language of the webpage, but the language is not supported by the translation server because it is too minor. This metric allows us to assess how important the unsupported language is for Google translate.

The time from a page content language being determined to user requesting Chrome Translate.

Distribution of the low entropy source value used for field trial randomization, recorded on startup.

A count of successes and various failure modes related to collecting and processing performance data obtained through "perf" on ChromeOS.

Deprecated 1/2013. No longer tracked.

A count of the number of times we hit the code where a field trial is disabled because no entropy provider was provided.

The counts of network error codes encountered by VariationsService when an attempt to fetch a variations seed from the server fails.

The latency of a VariationsService seed fetch that results in a not modified response.

The latency of a VariationsService seed fetch that results in neither a success nor not modified response.

The latency of a VariationsService seed fetch that results in a success response.

How long it took to create the X-Chrome-Variations header.

Deprecated 9/2012. No longer tracked.

Whether or not the network was available when requested by the VariationsService.

Counts the number of times the VariationsService is allowed or not allowed to make a request due to the ResourceRequestAllowedNotifier.

Records whether the variations seed in local state is empty (does not exist) on startup.

The counts of HTTP response codes encountered by VariationsService when attempting to fetch a variations seed from the server.

The time interval between when the Variations seed was last downloaded and when it was used.

Deprecated 11/2012. No longer tracked.

Whether or not the 1-Percent uniformity trial from the Variations server was expired when loaded.

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.

Deprecated 1/2013. No longer tracked.

A count of the number of times we hit the code where the UMA-Uniformity-Trial-1-Percent field trial is disabled as a result of the expiration check.

Deprecated 1/2013. No longer tracked.

Tracks whether the UMA-Uniformity-Trial-1-Percent field trial was not active and which factors contributed to it.

Measures the time taken by Google Online Wallet server's accept legal document API call.

Measures the time taken by Google Online Wallet server's authenticate instrument API call.

Measures the time taken by Google Online Wallet server's get full wallet API call.

Measures the time taken by Google Online Wallet server's get wallet items API call.

Measures the time taken by Google Online Wallet server's save address API call.

Measures the time taken by Google Online Wallet server's save instrument API call.

Measures the time taken by Google Online Wallet server's save instument and address API call.

Measures the time taken by Google Online Wallet server's send status API call.

Measures the time taken by Google Online Wallet server's unknown API calls.

Measures the time taken by Google Online Wallet server's update address API call.

Measures the time taken by Google Online Wallet server's update instument API call.

Count of how many instances of WebCore::Page use various features. Each WebCore::Page instance has a WebCore::UseCounter instance. It records and reports feature usage (e.g. via UseCounter::count() method).

Records usage of CSS properties used on a page, either statically or dynamically, from the time the page is initialised to when it is closed or navigated away from. Each property is counted at most once per page per view.

Every time a CSS property is parsed on a page, that property is recorded as having been used. The histogram is updated with this data whenever a page is closed, or a page navigation happens. Each histogram bucket corresponds to a CSS property (eg width, border-radius). The exception is the bucket numbered '1' - this counts the number of pages that CSS properties were counted on. These numbers give the percentage of pages that use a CSS property. For example, if the 'border-radius' histogram bucket has a count of 250, and the page count bucket (i.e. bucket number 1) has a count of 1000 - this means that 1000 pages were recorded, and border-radius was used on 25% of those pages. Internally, each WebCore::Page has a WebCore::UseCounter instance, with booleans recording use of each CSS property - one boolean per property. Upon destruction of the WebCore::Page (e.g. by the user closing the tab), or a page navigation happening, the histogram is updated. For each boolean that is set to True, the corresponding histogram bucket for that CSS property is incremented by 1. The page count bucket (i.e. bucket number 1) is always incremented by 1 on each histogram update.

Methods that encountered consistency errors. Such errors probably point to a bug in our code.

As of chrome 26, use {Consistency, Read, Write}Error instead.

Count of internal IndexedDB errors (data corruption, I/O errors, etc) encountered.

Count of the different success and failure modes when opening an IndexedDB backing store - clean open, successful open with recovery, failed recovery, etc.

Methods that encountered leveldb errors while trying to read from disk.

Methods that encountered leveldb errors while trying to write to disk.

Count total number of front end API calls of IndexedDB methods.

Count of how many times LevelDBDatabase got an error trying to check free disk space.

Amount of free disk space on the partition/volume/etc where LevelDB failed to open.

Amount of free disk space on the partition/volume/etc where LevelDB was successfully opened.

Error classes returned by LevelDB when it failed to open a database.

LevelDBEnv methods that generated IO errors when opening a database.

Error classes returned by LevelDB when it failed to write to a database.

LevelDBEnv methods that generated IO errors when writing to a database.

Duration of time taken to create a V8 Context for an isolated world.

Duration of time taken to create a V8 Context for the main world.

Count the number of WebSocket handshake for each result. Use this histogram as a baseline for investigating feature usage counters.

Count the number of WebSockets that accepted permessage-deflate extension for each context take over mode.

Count the number of XHR.send() calls for each argument type to see when we can deprecate the ArrayBuffer type support.

The time it takes for a webfont download to finish, for webfonts of under 10KB.

The time it takes for a webfont download to finish, for webfonts of 10KB-50KB.

The time it takes for a webfont download to finish, for webfonts of 50KB-100KB.

The time it takes for a webfont download to finish, for webfonts of 100KB-1MB.

The time it takes for a webfont download to finish, for webfonts of over 1MB.

The time taken for a webfont download that failed. Includes aborted requests.

Whether a locallly installed font is actually used when @font-face had local sources.

The number of webfonts used in a page. This is recorded when the first layout is done, and so will not count webfonts dynamically loaded by scripts.

Percentage of results that are present locally but are not returned by the web history API call. Recorded every time a signed-in user visits the chrome://history page and the results from the web history are received.

Whether getting the OAuth token was successful for a web history query. On visits to the chrome://history page this token is obtained and then used to get the user's synced web history.

HTTP Response code returned by the server when trying to fetch the OAuth token for a web history query.

Whether the web history API call was successful. Every time a signed-in user visits the chrome://history page this query is executed to get the user's synced web history. If successful, the local and remote results are merged and shown in the history page.

Time it took for the web history to reply. Recorded when the web history API call triggered by visiting chrome://history receives the data, measuring how much time it took for the server to reply.

Duration in milliseconds of WebRTC audio capture session.

Audio input channel layout in WebRTC.

Size of WebRTC audio input buffers (in audio frames).

Size of WebRTC audio input buffers (atypical values, in audio frames).

Audio input sample rate for WebRTC (in Hz).

Audio input sample rate for WebRTC (atypical values, in Hz).

Audio output channel layout in WebRTC.

Size of WebRTC audio output buffers (in audio frames).

Size of WebRTC audio output buffers (atypical values, in audio frames).

Audio output sample rate for WebRTC (in Hz).

Audio output sample rate for WebRTC (atypical values, in Hz).

Duration in milliseconds of WebRTC audio render session.

Counts number of calls to WebRTC APIs from JavaScript.

Incremented each time the TimeTicks field trial runs on a machine with multiple cores, but failed to change thread affinity. Broken down by Windows version.

The smallest non-zero delta reported by subsequent calls to QueryPerformanceCounter.

True if the CPU's time stamp counter ticks at a constant rate regardless of CPU frequency.

The number of times the TimeTicks field trial failed because QueryPerformanceCounter ticked backwards. Broken down by Windows version.

The number of times the TimeTicks field trial succeeded. Broken down by Windows version.

The number of times the TimeTicks field trial ran for comparison with WinTimeTicks.VersionSuccess. Broken down by Windows version.

The number of results (either query or URL) from ZeroSuggest. This is set every time a successful response from ZeroSuggest is recieved, which can be every time the user focuses on the omnibox.

The number of query results returned from ZeroSuggest. This is set every time a successful response from ZeroSuggest is recieved, which can be every time the user focuses on the omnibox.

The number of URL results returned from ZeroSuggest. This is set every time a successful response from ZeroSuggest is recieved, which can be every time the user focuses on the omnibox.

Results of DnsResponse::ParseToAddressList.

Succeeded with async DNS. Succeeded with getaddrinfo after async DNS failed. Both async DNS and getaddrinfo failed. Same as PROC_SUCCESS except the hostname fits NetBIOS name criteria. Started. Failed to start watching config. Failed to start watching HOSTS. Failed during watching config. Failed during watching HOSTS.

Connection type as defined in net/base/connection_type_histograms.h

Any connection (SSL, HTTP, SPDY, etc.) An SSL connection An SSL connection with an MD5 certificate in the certificate chain (excluding root) An SSL connection with an MD2 certificate in the certificate chain (excluding root) An SSL connection with an MD4 certificate in the certificate chain (excluding root) An SSL connection with an MD5 CA certificate in the certificate chain (excluding root) An SSL connection with an MD2 CA certificate in the cerfificate chain (excluding root) An HTTP connection A SPDY connection An SSL connection that uses SSL 2.0 An SSL connection that uses SSL 3.0 An SSL connection that uses TLS 1.0 An SSL connection that uses TLS 1.1 An SSL connection that uses TLS 1.2

Reason why a cookie was removed from the cookie store

The user explicitly requested that we delete a cookie The value of the cookie was overwritten by a new value The cookie expiration time passed The cookie was evicted during garbage collection (replaced by domain_evicted/global_evicted below) The backing store had two copies of the cookie so one was removed (i.e. problems writing the backing store database) The cookie deletion should not be recorded because it occurred, e.g., during shutdown (the fact that these values showed up in the histogram is a bug, since fixed) The cookie was evicted during per-domain/eTLD+1 garbage collection The cookie was evicted during whole store garbage collection. The cookie evicted during per-domain/eTLD+1 garbage collection, and would have been evicted by the global garbage collection process (because they hadn't been accessed recently enough). The cookie evicted during per-domain/eTLD+1 garbage collection, and would not have been evicted by global metrics as well (because they had been accessed recently enough to save). The cookie deletion occurred because the server overwrote it with an already expired cookie (this is a common idiom for server deletions of cookies). 127.0.0.1 was not the only nameserver in the system DNS config. 127.0.0.1 was the only nameserver in the system DNS config. Channel ID was enabled, but the client did not support elliptic curve key generation. Channel ID was enabled, but the client had an invalid system time which prevented using it. The SSLClientSocket was created without a ServerBoundCertService.

Status codes produced by DeviceManagementService for requests made to the device management server.

Result of DMToken operations as defined in chrome/browser/policy/enterprise_metrics.h.

A cached token was successfully loaded from disk. Reading a cached token from disk failed. A token fetch request was sent to the DM server. The request was invalid, or the HTTP request failed. Error HTTP status received, or the DM server failed in another way. A response to the fetch request was received. The response received was invalid. This happens when some expected data was not present in the response. DM server reported that management is not supported. DM server reported that the given device ID was not found. DM token successfully retrieved. Successfully cached a token to disk. Caching a token to disk failed. The Device-ID is not unique. Serial number rejected by DMServer. No more licenses available for that domain.

Result of device enrollment as defined in chrome/browser/policy/enterprise_metrics.h.

The enrollment screen was closed without completing the enrollment process. The user submitted credentials and started the enrollment process. Enrollment failed due to a network error. Enrollment failed because logging in to Gaia failed. Enrollment failed because it is not supported for the account used. Enrollment failed because it failed to apply device policy. Enrollment failed due to an unexpected error. This currently happens when the Gaia auth token is not issued for the DM service, the device cloud policy subsystem isn't initialized, or when fetching Gaia tokens fails for an unknown reason. Enrollment was successful. Serial number doesn't belong to account domain. Auto-enrollment started automatically after sign-in. Auto-enrollment failed. Auto-enrollment started again after a failure. User opted-out of auto-enrollment. Auto-enrollment OK. The enrollment mode has not been sent down or is unknown to the client. The enrollment mode can not be set through auto-enrollment. Install attributes failed to initialize in time. Re-enrollment attempted with an account from a different domain. No licenses left for that domain.

Status codes produced by the policy loaders that pull policy settings from the platform-specific management infrastructure, such as Windows Group Policy.

Policy load attempt started. This gets logged for each policy load attempt to get a baseline on the number of requests, and an arbitrary number of the below status codes may get added in addition. System failed to determine whether there's policy. No policy present. Data inaccessible, such as non-local policy file. Data missing, such as policy file not present. Trying with Wow64 redirection disabled. Data read error, for example file reading errors. Data too large to process. Parse error.

Result of Policy operations as defined in chrome/browser/policy/enterprise_metrics.h.

A cached policy was successfully loaded from disk. Reading a cached policy from disk failed. A policy fetch request was sent to the DM server. The request was invalid, or the HTTP request failed. Error HTTP status received, or the DM server failed in another way. Policy not found for the given user or device. DM server didn't accept the token used in the request. A response to the policy fetch request was received. The policy response message didn't contain a policy, or other data was missing. Failed to decode the policy. The device policy was rejected because its signature was invalid. Rejected policy because its timestamp is in the future. Device policy rejected because the device is not managed. The policy was provided for a username that is different from the device owner, and the policy was rejected. The policy was rejected for another reason. Currently this can happen only for device policies, when the SignedSettings fail to store or retrieve a stored policy. The fetched policy was accepted. The policy just fetched didn't have any changes compared to the cached policy. Successfully cached a policy to disk. Caching a policy to disk failed.

Reasons the sandboxed extension unpacker can fail. See enum FailureReason in src/chrome/browser/extensions/sandboxed_extension_unpacker.h .

SSL version fallback did not occur. Fell back on SSL 3.0. Fell back on TLS 1.0. Fell back on TLS 1.1. Data connection successful Local firewall blocked the connection Connection timed out Connection has been established, but then got broken (either reset or aborted) Connection has been refused Other kind of error

FTP server type as defined in net/ftp/ftp_server_type_histograms.h

Unknown (could be a server we don't support, a broken server, or a security attack) Server using /bin/ls -l and variants Server using /bin/dls Server using EPLF format WinNT server configured for old style listing VMS (including variants) IBM VM/CMS, VM/ESA, z/VM formats OS/2 FTP Server win16 hosts: SuperTCP or NetManage Chameleon Deprecated 9/2012, and replaced by DriveEntryKind Perf data was collected, parsed and attached to the UMA protobuf successfully. Could not add perf data to the UMA protobuf because no perf data was ready to be uploaded. Perf timer triggered but the perf provider already had a perf data proto to be added to the UMA protobuf. Perf timer triggered but an incognito window was open. Perf data was collected but an incognito window was opened during the collection. Perf data was collected and sent to Chrome as a serialized protobuf but it could be deserialized by Chrome.

Events in Google Now component extension. See var DiagnosticEvent.

newly connected socket connected unused socket (idle prior to use) previously used (keep-alive?) socket IndexedDB encountered an error attempting to read or decode a value from the leveldb backing store, indicative of corruption or I/O error. Unused as of M26. IndexeDB encountered an error attempting to write or commit a value to the leveldb backing store, indicative of I/O error. Unused as of M26. IndexedDB encountered a consistency error in the leveldb backing store, indicative of corruption or an coding error. Unused as of M26. An in-memory backing store was opened successfully. An on-disk backing store was opened successfully. An on-disk backing store could not be opened or created because the directory could not be opened or created. Cleanup will not be attempted. An on-disk backing store was opened but had an unknown schema version, due to corruption or reverting to a previous version of Chrome. Cleanup will be attempted. An on-disk backing store failed to open; cleanup was attempted but the database could not be destroyed. An on-disk backing store failed to open; cleanup was attempted but re-opening the database failed. An on-disk backing store failed to open; cleanup was attempted and the database was then opened successfully. An on-disk backing store was opened but leveldb failed to read the schema version. An in-memory backing store failed to open. A database with non-ascii characters in its path was opened (with either success or failure). An open failed on a machine with a full disk. No cleanup was attempted. IE (Windows-only) Firefox 2 Firefox 3 (and later) Safari (Mac-only) Google Toolbar A bookmarks.html file getifaddrs or GetAdaptersAddresses failed

ISO 639 Language Codes.

Not yet initialized User pressed reload Back or forward User entered URL, or omnibox search (deprecated) Included next 4 categories Commonly following of link JS/link directed reload back/forward or encoding change Allow stale data (avoid doing a re-post) Speculative prerendering of a page

These error indexes are produced by QCErrorToMetricIndex() in gobi-cromo-plugin.

Status code that we received in response to a cellular usage API request.

This value is distinct from the others in that it indicates that we were unable to issue a request or that we received no reply. The other values represent the status code contained in a reply.

The portal result types come from PortalResult in shill/metrics.h

The security types come from the connman_service_security enum in flimflam/include/service.h

The error types come from the connman_service_error enum in flimflam/include/service.h

These values are defined inside the PromoImpressionBuckets enum in chrome/browser/ui/webui/ntp/android/promo_handler.cc

Errno values with the same meanings on Mac/Win/Linux.

No error Operation not permitted No such file or directory No such process Interrupted function call Input/output error No such device or address Arg list too long Exec format error Bad file descriptor No child processes Resource deadlock avoided Cannot allocate memory Permission denied Bad address Not a block device Resource busy File exists Improper link Operation not supported by device Not a directory Is a directory Invalid argument Too many open files in system Too many open files Inappropriate ioctl for device Text file busy File too large Device out of space Illegal seek Read-only file system Too many links Broken pipe Numerical argument out of domain Numerical result out of range

Direction of the overscroll gesture.

Scrolled from bottom towards top Scrolled from top towards the bottom Scrolled from right towards left Scrolled from left towards right An operation was attempted during an incompatible decoder state. Invalid argument was passed to an API method. Encoded input is unreadable. A failure occurred at the browser layer or lower. Examples of such failures include GPU hardware failures, GPU driver failures, GPU library failures, browser programming errors, and so on. deprecated May 10 2012 Running in a IPv4-only configuration. No waste. Cache contained an UNSPEC result for this IPv4 lookup. Waste. Cache contained an IPv4 result for this UNSPEC lookup. Waste. Job pool contained an UNSPEC job for this IPv4 lookup. Waste. Job pool contained an IPv4 job for this UNSPEC lookup. Waste. A new job was needed for this IPv4 lookup. No waste. A new job was needed for this UNSPEC lookup. No waste. Deprecated 9/2012. No longer generated.

The termination action result types come from TerminationActionResult in shill/metrics.h

Legacy error codes still returned by |ShFileOperation()|

Error codes returned by SQLite - see sqlite3.h

Successful result SQL error or missing database NOT USED. Internal logic error in SQLite Access permission denied Callback routine requested an abort The database file is locked A table in the database is locked A malloc() failed Attempt to write a readonly database Operation terminated by sqlite3_interrupt() Some kind of disk I/O error occurred The database disk image is malformed NOT USED. Table or record not found Insertion failed because database is full Unable to open the database file NOT USED. Database lock protocol error Database is empty The database schema changed String or BLOB exceeds size limit Abort due to contraint violation Data type mismatch Library used incorrectly Uses OS features not supported on host Authorization denied Auxiliary database format error 2nd parameter to sqlite3_bind() out of range File opened that is not a database file sqlite3_step() has another row ready sqlite3_step() has finished executing TBD TBD Error reading from file TBD Short read from file Error writing to file (other than SQLITE_FULL) Error syncing to disk Error syncing directory changes to disk Error truncating file Error reading file metadata Error unlocking file Error getting read lock - should not be possible Error deleting file Deadlock due to other process access to SQLite files Error mapping shared memory Error getting file attributes (other than not found) Error while querying lock status Error acquiring lock Error closing file Unused Error mmapping file Error in stat while mmapping file Unused Replaced 5/14/2013 by expanded Sqlite.Error histogram.

Extended error codes returned by SQLite - see sqlite3.h

No extended code given Error reading from file Short read from file Error writing to file (other than SQLITE_FULL) Error syncing to disk Error syncing directory changes to disk Error truncating file Error reading file metadata Error unlocking file Error getting read lock - should not be possible Error deleting file Deadlock due to other process access to SQLite files Error mapping shared memory Error getting file attributes (other than not found) Error while querying lock status Error acquiring lock Error closing file Unused Error mmapping file Error in stat while mmapping file Unused No touchpad detected on a device without built-in touchpad External touchpad detected on a device without built-in touchpad Built-in touchpad not detected at boot time on a device with built-in touchpad (touchpad failure at boot time) Built-in touchpad detected at boot time on a device with built-in touchpad Built-in touchpad not detected at resume time on a device with built-in touchpad (touchpad failure at resume time) Built-in touchpad detected at resume time on a device with built-in touchpad All observed input events from touchpad. Serves as a reference. The touchpad noise events (e.g. abrupt cursor jumps) caused by the noisy ground. Failed Succeeded Timed out

Deprecated 2013-04 in favor of LevelDBEnvRetry.

deprecated May 10 2012