tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 22aa63fd7b1a2163fab7c977e309f75639e3e6fb..d7cd632147812260c39ecee01620d10a335842b1 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -18599,7 +18599,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram name="Extensions.InjectEnd_Time" units="ms">
   <owner>rdevlin.cronin@chromium.org</owner>
   <summary>
-    Time taken to inject all scripts at document end by extensions.
+    Time taken to inject all scripts at document end by extensions. Not reported
+    if scripts are executed asynchronously.
   </summary>
 </histogram>
 
@@ -18618,7 +18619,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram name="Extensions.InjectIdle_Time" units="ms">
   <owner>rdevlin.cronin@chromium.org</owner>
   <summary>
-    Time taken to inject all scripts at document idle by extensions.
+    Time taken to inject all scripts at document idle by extensions. Not
+    reported if scripts are executed asynchronously.
   </summary>
 </histogram>
 
@@ -18650,7 +18652,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram name="Extensions.InjectStart_Time" units="ms">
   <owner>rdevlin.cronin@chromium.org</owner>
   <summary>
-    Time taken to inject css/scripts at document start by extensions.
+    Time taken to inject css/scripts at document start by extensions. Not
+    reported if scripts are executed asynchronously.
   </summary>
 </histogram>
 
@@ -123120,6 +123123,13 @@ from previous Chrome versions.
   <affected-histogram name="Setup.Install.LzmaUnPackStatus"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="UserScriptRunLocation" separator=".">
+  <suffix name="DocumentStart" label="Scripts with run_at: document_start."/>
+  <suffix name="DocumentEnd" label="Scripts with run_at: document_end."/>
+  <suffix name="DocumentIdle" label="Scripts with run_at: document_idle."/>
+  <affected-histogram name="Extensions.InjectedScriptExecutionTime"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="V8SpecialApps" separator=".">
   <suffix name="calendar" label="Custom histogram for Calendar"/>
   <suffix name="docs" label="Custom histogram for Google Docs and Drive"/>