michaeln@chromium.org The number of after-startup tasks that were queued prior to startup completion and deferred until that time. michaeln@chromium.org Time from the process creation until deferred after-startup tasks began running. The histogram was expired and extended in M119 again. mthiesse@chromium.org pasko@chromium.org Records the first type of component created after process creation - most likely the reason the process was created - at the time the component is created on Android P+. Differences in distribution between Android versions (particularly with respect to ContentProviders) likely indicate a change to Android startup that broke our detection. hanxi@chromium.org wychen@chromium.org Records whether or not the cached Feed visibility in the SharedPreferences is consistent with the Feed visibility user preference on the disk. It's recorded when overview mode is shown because of Return to Tab Switcher, and only on cold start. By recording this histogram, the number of mismatches between the criteria of whether the Feed placeholder of Instant Start pre-native is shown and the criteria of whether Feed articles after native initialization are shown is recorded. blundell@chromium.org yfriedman@chromium.org Records whether the first navigation commit after a cold start occurred before UmaUtils.hasComeToForegroundWithNative() became true. Recorded only for startups in which startup metrics were being tracked. blundell@chromium.org yfriedman@chromium.org Records whether the first paint of StartupPaintPreview after a cold start occurred before UmaUtils.hasComeToForegroundWithNative() became true. Recorded only for startups in which startup metrics were being tracked. xinghuilu@chromium.org chrome-counter-abuse-alerts@google.com The time it took GmsCore SafeBrowsing API to respond to SafeBrowsing request (either through hash-prefix database or hash-prefix real time) in the process lifetime. Recorded at the same time as Startup.Android.Cold.TimeToFirstNavigationCommit.Tabbed. Only logged if the URL of the first navigation is checked by SafeBrowsing API. pasko@chromium.org xinghuilu@chromium.org chrome-counter-abuse-alerts@google.com The time it took GmsCore SafetyNet API to respond to the first hash-prefix SafeBrowsing database request in the process lifetime. Recorded at the same time as Startup.Android.Cold.TimeToFirstNavigationCommit.Tabbed. Only logged if the URL of the first navigation is checked by SafetyNet API. pasko@chromium.org alexilin@chromium.org Android: The time from the activity creation point to the first contentful paint of the first loaded page. It's not recorded when the first loaded page is non http(s) page like a chrome error page, a new tab page, a blank page. It's also not recorded if the application wasn't in the foreground since the start till the end of event. pasko@chromium.org alexilin@chromium.org Android: The time from the activity creation point to the moment the first navigation is committed, i.e. when renderer gets the first byte of the document. It's not recorded when the first loaded page is non http(s) page like a chrome error page, a new tab page, a blank page. It's also not recorded if the application wasn't in the foreground since the start till the end of event. pasko@chromium.org agrieve@chromium.org Experimental. Same as Startup.Android.Cold.TimeToFirstNavigationCommit.Tabbed with two modifications. The first difference is to record navigation commits happening before post-native initialization. The second modifications is not to record samples when FRE is shown. yfriedman@chromium.org pasko@chromium.org fredmello@chromium.org chrome-analysis-team@google.com The time from Chrome tabbed activity creation to the moment the Chrome first appears ready. This metric captures when the omnibox is painted and either a navigation has committed or a Paint Preview is shown. The intent is to reflect Clank's perceived cold start performance regardless of different launch paths, while controlling for the factors that we have the most direct influence over and minimizing external factors. Note that network connectivity is mostly but not entirely omitted as it does impact the initial response time for a site which impacts the omnibox UX and loading metric. This metric captures the value of the first emitted metric out of the 'Startup.Android.Cold.TimeToFirstNavigationCommit.Tabbed' and 'Browser.PaintPreview.TabbedPlayer.TimeToFirstBitmap' metrics and emits the value. This metric is only recorded once per application lifetime during cold startup i.e. when Chrome's native library is not loaded at first activity creation. Specifically, it is recorded for the first foreground committed http(s) URL in the primary frame if that first navigation is not: an error, same-document navigation, or fragment navigation. This metric is expected be stable from milestone to milestone. Updating Chrome or the Android system image on the device are expected to result in a noticeable slowdown on the first cold startup after. The total counts changes for this histogram are not of significant importance; however, a non-trivial increase in total counts could signal more background kills, for example. This metric is not recorded: - If another navigation occurs before the first navigation commit and the Paint Preview show. - If the navigation is pre-warmed, is a background navigation, or fails to be committed (e.g. cancelled, network error, or error due to lack of connectivity). - If the activity was ever backgrounded between activity creation and this metric reporting. - If the app opens to the Chrome Start page. - For WebApps, PWAs or WebApks. Bugs: - This metric does not get recorded when the first navigation commit happens before post-native initialization. This behaviour is not intentional, see crbug.com/1273097. TimeToFirstVisibleContent2 addresses this issue. This histogram is of special interest to the chrome-analysis-team@. Do not change its semantics or retire it without talking to them first. yfriedman@chromium.org pasko@chromium.org fredmello@chromium.org The time from Chrome tabbed activity creation to the moment the Chrome first appears ready. Currently experimental. Has the same semantics as Startup.Android.Cold.TimeToFirstVisibleContent, without the known bug. pasko@chromium.org mthiesse@chromium.org The time from activity creation till the point when UMA foreground session starts. ckitagawa@chromium.org Android: The time from the activity creation point to the moment the content may first appear ready to a user. The intent is to capture readiness of Chrome regardless of whether Chrome is launched into native UI or a web page. The recorded value is the minimum of 'Startup.Android.Cold.TimeToFirstContentfulPaint.Tabbed' and 'Browser.PaintPreview.TabbedPlayer.TimeToFirstBitmap' metric values. Not to be mistaken with the Startup.Android.Cold.TimeToFirstVisibleContent histogram, as this metric is intended for the use of the Paint Preview owners and the other is intended to track Clank's perceived cold start performance. hanxi@chromium.org Android: The elapsed time from the last time when Chrome goes to background till it becomes foreground again. The histogram is recorded when onResumeWithNative() is called. hanxi@chromium.org wychen@chromium.org Records the time duration from a cold start till the Feeds articles are first loaded on the StartSurface. This histogram is only recorded when StartSurface is shown at launch due to "return to tab switcher" feature. hanxi@chromium.org wychen@chromium.org Records the time duration from a cold start till the Feeds loading placeholder is shown on the StartSurface. This placeholder is only shown when the feature flag InstantStart is enabled and StartSurface is shown at launch due to "return to tab switcher" feature. hanxi@chromium.org wychen@chromium.org Records the time duration from a cold start till the Feeds stream is created on the StartSurface. This histogram is only recorded when StartSurface is shown at launch due to "return to tab switcher" feature. hanxi@chromium.org wychen@chromium.org Records the time duration from a cold start till the first draw completes. mthiesse@chromium.org yfriedman@chromium.org Measures the amount of time startup has likely been delayed due to GURL waiting on the native library to be initialized. hanxi@chromium.org xinyiji@chromium.org Records whether the HompagePolicyManager is initialized with native in startup when the check of whether to show Start surface when there isn't any Tab happens. The histogram is recorded only on startup when Chrome is launched from app icon and there isn't any Tab to restore. hanxi@chromium.org xinyiji@chromium.org Android: Records whether the last time when Chrome went to background or closed was logged. The histogram is recorded when onResumeWithNative() is called. hanxi@chromium.org xinyiji@chromium.org Android: Records whether the last time when Chrome was showing in foreground was logged. The histogram is recorded when onResumeWithNative() is called. hanxi@chromium.org fredmello@chromium.org Records whether or not the last visited tab is a search result page when StartSurface is shown at launch. This histogram is only recorded when StartSurface is shown at launch due to "return to tab switcher" feature. tommasin@chromium.org kartoffel-core-eng@google.com Android: PrivacySandbox dialog not shown because Chrome Tab was launched from an external app. hanxi@chromium.org wychen@chromium.org Records the time duration from a cold start till the title of the single Tab is shown on the StartSurface. This histogram is only recorded when StartSurface is shown at launch due to "return to tab switcher" feature. hanxi@chromium.org wychen@chromium.org Records whether the Start surface homepage is showing at a cold startup when the Start surface is enabled. This histogram is recorded in a deferred startup task after Chrome is launched. mark@chromium.org crashpad-dev@chromium.org The amount of time that elapsed during in crash_report::BlockUntilHandlerStarted(). peter@chromium.org Records the cause, each time Chrome is brought to the foreground. Currently only checks if a NotificationUIManager notification was shown in the last 5 seconds (includes Web Notifications, but not media or Cast). robliao@chromium.org The amount of time that elapsed during BrowserMainRunnerImpl::Initialize. gab@chromium.org etienneb@chromium.org Time from application start to the first time MainMessageLoopRun() reaches idle. This is a new (Feb'2021) metric intended to capture UI jank caused by the long queue of tasks post initialization. This is believed to capture performance issues (startup responsiveness) none of the other Startup.* metrics capture (crbug.com/1175074). Recording is dropped if blocking UI is shown before first-idle is reached (as this blocks main loop progress on unbounded user interaction). etienneb@chromium.org gab@chromium.org Time between Startup.BrowserMessageLoopStartTime and Startup.FirstWebContents.NonEmptyPaint2. Recorded explicitly to allow easy breakdown of Startup.FirstWebContents.NonEmptyPaint2 when diagnosing issues. chrisha@chromium.org fdoray@chromium.org The number of hard faults incurred in the browser process from startup to start of the main thread's message loop, not including first runs of the browser. fdoray@chromium.org gab@chromium.org Time from application start to the start of the main thread's message loop. Not recorded for first run. April 8, 2020: Changed the reference from process creation to application start. See Startup.FirstWebContents.NonEmptyPaint3 for a definition of application start. fdoray@chromium.org gab@chromium.org Time from application start to the start of the main thread's message loop. Recorded for a first run of the browser. April 8, 2020: Changed the reference from process creation to application start. See Startup.FirstWebContents.NonEmptyPaint3 for a definition of application start. rkaplow@chromium.org The amount of time that elapsed during BrowserProcessImpl::PreMainMessageLoopRun. gab@chromium.org mblsha@yandex-team.ru Time from application start to the time the first Browser window has finished painting its children. April 8, 2020: Changed the reference from process creation to application start. See Startup.FirstWebContents.NonEmptyPaint3 for a definition of application start. fdoray@chromium.org gab@chromium.org Time from application start to the time the browser window initially becomes visible. April 8, 2020: Changed the reference from process creation to application start. See Startup.FirstWebContents.NonEmptyPaint3 for a definition of application start. djean@chromium.org olivierrobin@chromium.org chrome-analysis-team@google.com The duration of all initializations from process creation time to UI ready to receive input. iOS specific, from M91+ The process can only be created in response to a user action, either tapping the icon, tapping a link that opens in Chrome, or using the app switcher to switch to Chrome after it has been background-killed by the OS. The metric is recorded at the point where the Chrome window starts receiving input events like touches and keypresses. However, the Chrome splash screen is showing at this point, so there aren't any UI elements for a user to interact with. It includes code loading and static initializers. The total counts in this histogram can be compared with the number of emits to the user action MobileWillEnterForeground. The former reports the number of cold starts. The latter is only recorded when Chrome comes to the foreground on non-cold starts. Do not modify this metric in any way without contacting chrome-analysis-team@google.com. olivierrobin@chromium.org ajuma@chromium.org [IOS] The number of time [UIApplicationDelegate application:didFinishLaynching] was called but no scene was activated. Recorded when first scene is becomes active. olivierrobin@chromium.org ajuma@chromium.org [IOS] The number of time +load was called but no scene was activated. Recorded when first scene is becomes active. fdoray@chromium.org gab@chromium.org How long it takes to load the original profile synchronously on the UI thread. gab@chromium.org etienneb@chromium.org Records the time it took to complete upgrade_util::DoUpgradeTasks() when {Status}. fdoray@chromium.org gab@chromium.org [Desktop] The reason for which startup profiling was deemed complete. Logged once per session on startup. fdoray@chromium.org gab@chromium.org [Desktop] Measure the elapsed time from application start to the moment when the navigation is committed (first bytes received) in the first web contents' main frame. April 8, 2020: Changed the reference from process creation to application start. See Startup.FirstWebContents.NonEmptyPaint3 for a definition of application start. fdoray@chromium.org gab@chromium.org [Desktop] Measure the elapsed time from application start to the beginning of navigation in the first web contents' main frame. April 8, 2020: Changed the reference from process creation to application start. See Startup.FirstWebContents.NonEmptyPaint3 for a definition of application start. etiennep@chromium.org fdoray@chromium.org gab@chromium.org chrome-analysis-team@google.com [Desktop] Measure the elapsed time from the application start to the first non empty paint of the first web contents. Only comprised of cases where the initial foreground tab gets to complete its rendering task unimpeded (an improvement over Startup.FirstWebContents.NonEmptyPaint). Application start is a time recorded as early as possible in the startup process. On Windows, application start is when chrome.exe:main starts, before chrome.dll is loaded. On other platforms, it is when ChromeMainDelegate is constructed. Do not modify this metric in any way without contacting chrome-analysis-team@google.com. spvw@chromium.org etienneb@chromium.org Time from when the application started to when the GPU finishes its initialization. Application start is a time recorded as early as possible in GPU process startup. On Windows, application start is at the start of the GPU process' chrome.exe:main, before chrome.dll is loaded. On other platforms, it is when ChromeMainDelegate is constructed. It should be noted that this does not include rendezvous starts, since in that case, a new GPU process is not launched. This metric is recorded every time the GPU process finishes its initialization, including the case where the process restarts several times during the same browser session. This does not include the GPU info collection process, as that process does not use the GpuServiceImpl. spvw@chromium.org etienneb@chromium.org Time from when ChromeMain was entered in the GPU process to when the GPU finishes its initialization. This metric is recorded every time the GPU process finishes its initialization, including the case where the GPU process restarts several times during the same browser session. spvw@chromium.org etienneb@chromium.org Time from when the GPU process was created according to the OS, to when the GPU finishes its initialization. Mostly useful on Windows, where much time is spent in pre-main. This metric is recorded every time the GPU process finishes its initialization, including the case where the GPU process restarts several times during the same browser session. arabm@google.com chrome-incognito@google.com Records whether Incognito switch was present in commmand line switches and if Incognito mode was enforced or denied. This is recorded during browser startup when commandline is processed. jlebel@chromium.org chrome-signin-team@chromium.org Records session type for a cold start. It is recorded at cold start. Histogram only for iOS. fdoray@chromium.org etiennep@chromium.org gab@chromium.org Time from the application start to the C++ ChromeMain() function being invoked. fdoray@chromium.org etiennep@chromium.org gab@chromium.org Time from the process creation to application start, i.e. time recorded as early as possible in the startup process. thegreenfrog@chromium.org olivierrobin@chromium.org The action requested on the application startup when called from another app or the OS. thegreenfrog@chromium.org olivierrobin@chromium.org The calling application (if any). erikchen@chromium.org The amount of time that elapsed between main entry and the invocation of -[AppControllerMac awakeFromNib]. erikchen@chromium.org The amount of time that elapsed between main entry and the invocation of -[AppControllerMac didFinishLaunching:]. At that point, the dock icon will finish its current animation and stop bouncing. erikchen@chromium.org The amount of time that elapsed between main entry and the invocation of ChromeBrowserMainPartsMac::PostMainMessageLoopStart. erikchen@chromium.org The amount of time that elapsed between main entry and the invocation of ChromeBrowserMainPartsMac::PostProfileInit. erikchen@chromium.org The amount of time that elapsed between main entry and the invocation of ChromeBrowserMainPartsMac::PreMainMessageLoopStart. erikchen@chromium.org The amount of time that elapsed between main entry and the invocation of ChromeBrowserMainPartsMac::PreProfileInit. erikchen@chromium.org The amount of time that elapsed between main entry and the invocation of -[AppControllerMac willFinishLaunching:]. rkaplow@chromium.org The amount of time that elapsed during ChromeBrowserMainParts::PreMainMessageLoopRunImpl. spvw@chromium.org etienneb@chromium.org Time from application start to renderer run loop start. Application start is a time recorded as early as possible in renderer process startup. Application start is at the start of the renderer process' chrome.exe:main, before chrome.dll is loaded. This metric is only recorded on Windows, and is recorded every time a renderer process starts its run loop, meaning that many instances of this metric will be recorded throughout one execution of the browser. spvw@chromium.org etienneb@chromium.org Time from when ChromeMain in the renderer process was entered to when the renderer run loop was started. This metric is only recorded on Windows, and is recorded every time a renderer process starts its run loop, meaning that many instances of this metric will be recorded throughout one execution of the browser. spvw@chromium.org etienneb@chromium.org Time from when the renderer process was created (CreateProcess call) to when the renderer run loop is started. This metric is only recorded on Windows, and is recorded every time a renderer process starts its run loop, meaning that many instances of this metric will be recorded throughout one execution of the browser. djean@chromium.org olivierrobin@chromium.org The external application requesting showing the default browser settings. Logged when the command is received from the external application. Histogram only for iOS. rkaplow@chromium.org The amount of time that elapsed during StartupBrowserCreator::Start(). chrisha@chromium.org fdoray@chromium.org Indicates whether or not the given startup was warm, cold or unable to be determined. This is based off observing the number of hard faults that occur during startup prior to Startup.BrowserMessageLoopStartTime. The threshold for cold startup was updated Jan 2020, a bump in the metric is expected. olivierrobin@chromium.org ajuma@chromium.org [IOS] The duration between process spawn (returned by sysctl) and call to [UIApplicationDelegate didFinishLaunching:]. Recorded when first scene is becomes active. olivierrobin@chromium.org ajuma@chromium.org [IOS] The duration between process spawn (returned by sysctl) and library load (logged on +load method). Recorded when first scene is becomes active. olivierrobin@chromium.org ajuma@chromium.org [IOS] The duration between process spawn (returned by sysctl) and call to main. Recorded when first scene is becomes active. olivierrobin@chromium.org ajuma@chromium.org [IOS] The duration between process spawn (returned by sysctl) and call to the first scene connection. Recorded when first scene is becomes active.