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 feda2df020b534842121615c2e20a44789b5aec1..b814f25823906fcfda0c199150dcbfab3a59dab8 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -18409,6 +18409,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Extensions.InjectedScriptExecutionTime" units="ms">
+  <owner>ksakamoto@chromium.org</owner>
+  <summary>
+    Time taken to execute all scripts for one location within an extension.
+    Recorded every time content scripts injected by extensions are executed.
+    Unlike Extensions.InjectScriptTime, this includes execution time of

[Ilya Sherman, 2017/03/15 08:18:07]

Is it perhaps worth deprecating Extensions.InjectScriptTime?

[Kunihiko Sakamoto, 2017/03/16 07:39:02]

Devlin, is it okay to deprecate Extensions.InjectScriptTime?

[Devlin, 2017/03/16 14:56:17]

TL;DR: Yes.

Extensions.InjectScriptTime now measures the synchronous amount of time taken to
inject scripts, right?  In principle, that might still be useful information. 
In practice, it's probably too noisy without being broken down further (e.g.
into document_start et al) to really infer much from, because we don't know
whether the scripts will be executed sync, async, blocked, etc.  It might be
worth revisiting at a later date adding in a sync execution timer that has this
extra granularity, but my guess is that InjectScriptTime will probably just
confuse people.

+    asynchronously injected scripts.
+  </summary>
+</histogram>
+
 <histogram name="Extensions.InjectEnd_BlockingScriptCount">
   <owner>rdevlin.cronin@chromium.org</owner>
   <summary>