Improve iOS Startup / Foreground Metrics Descriptions
Improves the description of the histogram
Startup.ColdStartFromProcessCreationTimeV2.
Improve the description of the user action MobileWillEnterForeground.
Change-Id: Ib1c7a87dec60d1b9b49c88e6dda03bd49fd5cf5f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2832473
Reviewed-by: Ali Juma <ajuma@chromium.org>
Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Commit-Queue: Mark Pearson <mpearson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#873892}
diff --git a/tools/metrics/actions/actions.xml b/tools/metrics/actions/actions.xml
index 97e60f3..bed1d9c 100644
--- a/tools/metrics/actions/actions.xml
+++ b/tools/metrics/actions/actions.xml
@@ -16153,10 +16153,12 @@
<owner>olivierrobin@chromium.org</owner>
<owner>marq@chromium.org</owner>
<description>
- App transitioned from background to foreground. This action is directly or
- indirectly triggered by the user. Example of direct trigger: the user tapped
- on app icon or choose the app in app switcher. Example of indirect trigger:
- the user tapped on GMail link or used Today's View extension. iOS only.
+ App transitioned from background to foreground. Only recorded when the app
+ was previously running; i.e., not recorded on cold starts. This action is
+ directly or indirectly triggered by the user. Example of direct trigger: the
+ user tapped on app icon or choose the app in app switcher. Example of
+ indirect trigger: the user tapped on GMail link or used Today's View
+ extension. iOS only.
</description>
</action>
diff --git a/tools/metrics/histograms/histograms_xml/startup/histograms.xml b/tools/metrics/histograms/histograms_xml/startup/histograms.xml
index 32b5d5f2..1553d084 100644
--- a/tools/metrics/histograms/histograms_xml/startup/histograms.xml
+++ b/tools/metrics/histograms/histograms_xml/startup/histograms.xml
@@ -436,7 +436,7 @@
expires_after="2021-08-22">
<obsolete>
Removed 03/2021. Broken starting M-87; removed and replaced with
- Startup.ColdStartFromProcessCreationTime2 in M-91.
+ Startup.ColdStartFromProcessCreationTimeV2 in M-91.
</obsolete>
<owner>djean@chromium.org</owner>
<owner>olivierrobin@chromium.org</owner>
@@ -456,10 +456,26 @@
<owner>djean@chromium.org</owner>
<owner>olivierrobin@chromium.org</owner>
<summary>
- The duration of all initializations from process creation time to UI ready.
- This includes code loading, static initializers and the execution time
+ 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, static initializers and the execution time
contained in Startup.ColdStartWithExternalURLTime and
- Startup.ColdStartWithoutExternalURLTime metrics. iOS specific, from M91+.
+ Startup.ColdStartWithoutExternalURLTime metrics.
+
+ 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.
</summary>
</histogram>
