Bound the impact of system instability on chrome instability.

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 ee3db9d63c85171f2279bcd4d11dc51161a90867..c7371ec460294c0adeeb8f3297f0885ee05176a4 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -380,6 +380,15 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="ActivityTracker.Collect.SystemSessionAnalysisStatus"
+    enum="ActivityTrackerSystemSessionAnalysisStatus">
+  <owner>manzagop@chromium.org</owner>
+  <summary>
+    Status for the analysis of the system session state. Logged each time a
+    debug file is collected.
+  </summary>
+</histogram>
+
 <histogram name="ActivityTracker.Collect.TotalTime" units="ms">
   <owner>manzagop@chromium.org</owner>
   <summary>
@@ -79066,6 +79075,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="2" label="Get stability file path failed"/>
 </enum>
 
+<enum name="ActivityTrackerSystemSessionAnalysisStatus" type="int">
+  <int value="0" label="Success"/>
+  <int value="1" label="Missing timestamp"/>
+  <int value="2" label="Missing analyzer"/>
+  <int value="3" label="Analysis failed"/>

[Sigurður Ásgeirsson, 2017/03/07 14:38:39]

ah - this should allow you to bound the error rate. Missed that.

[manzagop (departed), 2017/03/07 15:49:02]

Acknowledged.

+  <int value="4" label="Outside range"/>
+</enum>
+
 <enum name="ActivityTrackerWriteDumpStatus" type="int">
   <int value="0" label="Sucess"/>
   <int value="1" label="Failed"/>