Quantify initial stability report edge cases.

components/metrics/metrics_pref_names.cc

Index: components/metrics/metrics_pref_names.cc
diff --git a/components/metrics/metrics_pref_names.cc b/components/metrics/metrics_pref_names.cc
index a578e574ad3a2d8e9911a6b6da9b4ca1bf9f6e80..c9ab88c5e80ee61ac101e9cc83687b1beafce81c 100644
--- a/components/metrics/metrics_pref_names.cc
+++ b/components/metrics/metrics_pref_names.cc
@@ -86,6 +86,15 @@ const char kStabilityChildProcessCrashCount[] =
 const char kStabilityCrashCount[] =
     "user_experience_metrics.stability.crash_count";
 
+// Number of times stability data upload were deferred.
+const char kStabilityDeferredCount[] =
+    "user_experience_metrics.stability.deferred_count";
+
+// Number of times stability data was discarded. This is accumulated since the
+// last report, even across versions.
+const char kStabilityDiscardCount[] =
+    "user_experience_metrics.stability.discard_count";
+
 // Number of times the browser has been run under a debugger.
 const char kStabilityDebuggerPresent[] =
     "user_experience_metrics.stability.debugger_present";
@@ -178,6 +187,11 @@ const char kStabilityStatsBuildTime[] =
 const char kStabilityStatsVersion[] =
     "user_experience_metrics.stability.stats_version";
 
+// The number of times the prefs version value did not match the serialized
+// system profile version value.
+const char kStabilityVersionMismatchCount[] =
+    "user_experience_metrics.stability.version_mismatch_count";
+
 // The keys below are strictly increasing counters over the lifetime of
 // a chrome installation. They are (optionally) sent up to the uninstall
 // survey in the event of uninstallation.