Quantify initial stability report edge cases.

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 f306e4efd6977bf52abe6738a3ef10dc6c9ab778..3b17ee4f808d76f9a3884ad8b85009cf09b208dc 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -57423,6 +57423,30 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Stability.InitialStabilityLog.DeferredCount">

[Alexei Svitkine (slow), 2016/09/02 17:57:49]

Nit: Add units= for all of these. Even if it's just units="counts".

[manzagop (departed), 2016/09/02 21:00:06]

Done.

+  <owner>manzagop@chromium.org</owner>
+  <summary>
+    Number of times the initial stability log upload was deferred to the next
+    startup.

[Alexei Svitkine (slow), 2016/09/02 17:57:49]

Nit: For all of these, mention when this is logged.

[manzagop (departed), 2016/09/02 21:00:06]

Done.

+  </summary>
+</histogram>
+
+<histogram name="Stability.InitialStabilityLog.DiscardCount">
+  <owner>manzagop@chromium.org</owner>
+  <summary>
+    Number of times stability data was discarded. This is accumulated since the
+    last report, even across versions.
+  </summary>
+</histogram>
+
+<histogram name="Stability.InitialStabilityLog.VersionMismatchCount">
+  <owner>manzagop@chromium.org</owner>
+  <summary>
+    Number of times the version number stored in prefs did not match the
+    serialized system profile version number.
+  </summary>
+</histogram>
+
 <histogram name="Stability.MobileSessionShutdownType"
     enum="MobileSessionShutdownType">
   <owner>lpromero@chromium.org</owner>