Stability instrumentation: metrics for collection on crash

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 6ed192b3a430a9c42cd098e58111a7082c27aa59..a5851d72c3a93b0da9f3aad8069a654883025dc6 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -449,8 +449,20 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="ActivityTracker.CollectCrash.Event"
+    enum="ActivityTrackerCollectCrashEvent">
+  <owner>manzagop@chromium.org</owner>
+  <summary>
+    Events that occur during crash collection of the debug file. Logged each
+    time an event of interest occurs during crash debug file collection.
+  </summary>
+</histogram>
+
 <histogram name="ActivityTracker.CollectCrash.OpenForDeleteSuccess"
     enum="BooleanSuccess">
+  <obsolete>
+    Deprecated 05/2017 in favor of ActivityTracker.CollectCrash.Event.
+  </obsolete>
   <owner>manzagop@chromium.org</owner>
   <summary>
     Success of the attempt to open the debug file for deletion. Logged each time