Stats collector for message center.

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 d8a3894a4dc1f671547d1e483fdeeb2aeda074c4..c61f8e1600f57e1cdf61812c28dc68abbf01227b 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -10195,6 +10195,20 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="Notifications.PerNotificationActions"
+    enum="NotificationActionType">
+  <summary>
+    The actions taken on notifications, recorded once per notification, when it
+    is closed.
+  </summary>
+</histogram>
+
+<histogram name="Notifications.RawActions" enum="NotificationActionType">
+  <summary>
+    The actions taken on notifications, recorded every time they happen.
+  </summary>
+</histogram>

[Ilya Sherman, 2013/09/21 05:43:29]

Why measure this in two different ways?  That is, why is the RawActions
histogram -- which I would probably rename to just 'Actions' -- insufficient?

+
 <histogram name="ntp.searchurls.total">
   <summary>TBD</summary>
 </histogram>
@@ -23616,6 +23630,17 @@ other types of suffix sets.
   <int value="4" label="User dismissed the promo"/>
 </enum>
 
+<enum name="NotificationActionType" type="int">
+  <int value="0" label="Unknown"/>
+  <int value="1" label="Notification added"/>
+  <int value="2" label="Notificaiton updated"/>
+  <int value="3" label="Notification clicked"/>
+  <int value="4" label="Notification button clicked"/>
+  <int value="5" label="Notification displayed"/>
+  <int value="6" label="Notification closed by user"/>
+  <int value="7" label="Notification closed by system"/>
+</enum>
+
 <enum name="NtpFollowAction" type="int">
   <int value="0" label="PAGE_TRANSITION_LINK"/>
   <int value="1" label="PAGE_TRANSITION_TYPED"/>