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 b2c49278b3d401d6689c3be9884f9b47feaa3a35..c691861d8ca8ea926778ab03081b9dd3b388020e 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -43932,6 +43932,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Platform.Crouton.Started" enum="Platform.Crouton.Started">
+  <owner>drinkcat@chromium.org</owner>
+  <summary>
+    Detects presence of /run/crouton, indicating that crouton has been started
+    since the previous boot.

[Alexei Svitkine (slow), 2017/01/06 16:18:19]

Nit: Mention when this is logged. Once on startup? Periodically? Something else?

+  </summary>
+</histogram>
+
 <histogram name="Platform.CrOSEvent" enum="CrosEventEnum">
   <owner>dkrahn@chromium.org</owner>
   <summary>
@@ -96955,6 +96963,11 @@ value.
   <int value="2" label="Error"/>
 </enum>
 
+<enum name="Platform.Crouton.Started" type="int">
+  <int value="0" label="Total count"/>

[Ilya Sherman, 2017/01/06 22:12:45]

I think it might be easier to interpret the data if this bucket were
semantically "Not started" rather than a total count.  Is that more difficult to
implement?

+  <int value="1" label="Started"/>
+</enum>
+
 <enum name="PlatformFileError" type="int">
   <int value="0" label="OK"/>
   <int value="1" label="FAILED"/>