Add UMA histogram data representing the Synced Notifications feature.

chrome/browser/notifications/message_center_stats_collector.cc

Index: chrome/browser/notifications/message_center_stats_collector.cc
diff --git a/chrome/browser/notifications/message_center_stats_collector.cc b/chrome/browser/notifications/message_center_stats_collector.cc
index f0257a94235cf2b6791f799bc47b8f687df646df..3b499f914ddd2820efff0300107215c7354dd86e 100644
--- a/chrome/browser/notifications/message_center_stats_collector.cc
+++ b/chrome/browser/notifications/message_center_stats_collector.cc
@@ -134,5 +134,11 @@ void MessageCenterStatsCollector::OnCenterVisibilityChanged(
 }
 
 void MessageCenterStatsCollector::OnQuietModeChanged(bool in_quiet_mode) {
+  if (in_quiet_mode)

[Alexei Svitkine (slow), 2013/10/11 14:50:12]

Nit: This needs {}.

[Pete Williamson, 2013/10/14 03:46:07]

Done.

+    content::RecordAction(
+        content::UserMetricsAction("Notification.Mute"));

[Alexei Svitkine (slow), 2013/10/11 14:50:12]

Please run tools/metrics/extract_actions.py and add the modified file to the CL.

[Pete Williamson, 2013/10/14 03:46:07]

Done, though the tool had some errors (I sent mail about it separately)

+  else
+    content::RecordAction(
+        content::UserMetricsAction("Notification.Unmute"));
 }