Added UMA statistics for Chrome Cleaner.

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 d65f0d3d557d9fdadb1118d1b55a98e6104beb71..61bb3922e9c722bd3030f7f6f62bcb9b01ceeda3 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -32884,6 +32884,21 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="SoftwareReporter.Cleaner.ExitCode">
+  <owner>mad@chromium.org</owner>
+  <summary>The exit code of the software reporter cleaner.</summary>
+</histogram>
+
+<histogram name="SoftwareReporter.Cleaner.RunTime" units="ms">
+  <owner>mad@chromium.org</owner>
+  <summary>The runtime of the he software reporter cleaner tool.</summary>

[Alexei Svitkine (slow), 2014/10/29 21:47:51]

Nit: "the he" -> "the"

I think "runtime" is ambiguous - as it could mean different things. I would
explicitly spell out "running time" or "How long it took to run the software
reporter cleaner."

Also, please mention in this description that you're logging crashes as the
maximum runtime, if you still want to do this.

[Georges Khalil, 2014/10/30 13:57:58]

Done.

+</histogram>
+
+<histogram name="SoftwareReporter.Cleaner.Version">
+  <owner>mad@chromium.org</owner>
+  <summary>The build version of the software reporter cleaner tool.</summary>
+</histogram>
+
 <histogram name="SoftwareReporter.MajorVersion">
   <owner>mad@chromium.org</owner>
   <summary>