GCM: Add Android UMA, and UMA for deleted/collapsed messages

components/gcm_driver/gcm_stats_recorder_impl.cc

Index: components/gcm_driver/gcm_stats_recorder_impl.cc
diff --git a/components/gcm_driver/gcm_stats_recorder_impl.cc b/components/gcm_driver/gcm_stats_recorder_impl.cc
index faa0cc7e8caeb05f04b2eb2d37cb54791ff79653..bd3559ddc2bd679dcaac781330edf3ce4d17972b 100644
--- a/components/gcm_driver/gcm_stats_recorder_impl.cc
+++ b/components/gcm_driver/gcm_stats_recorder_impl.cc
@@ -415,11 +415,24 @@ void GCMStatsRecorderImpl::RecordDataMessageReceived(
     const std::string& from,
     int message_byte_size,
     bool to_registered_app,
-    ReceivedMessageType message_type) {
-  UMA_HISTOGRAM_BOOLEAN("GCM.DataMessageReceivedHasRegisteredApp",
-                        to_registered_app);
-  if (to_registered_app)
-    UMA_HISTOGRAM_COUNTS("GCM.DataMessageReceived", 1);
+    ReceivedMessageType message_type,
+    bool has_collapse_key,
+    int deleted_count) {
+  switch (message_type) {
+    case GCMStatsRecorderImpl::DATA_MESSAGE:
+      UMA_HISTOGRAM_BOOLEAN("GCM.DataMessageReceivedHasRegisteredApp",

[Peter Beverloo, 2016/12/07 13:44:12]

This means that we're not recording this histogram anymore for deleted messages
messages.

[johnme, 2016/12/07 14:29:16]

That's deliberate - we don't really care about messages getting deleted for
non-existing registrations, and those registrations will still show up in UMA
stats when receive non-deleted messages; however it would be problematic (and
confusing given the name of the UMA) if the DataMessageReceivedHasRegisteredApp
count/ratio were skewed by DELETED_MESSAGES messages.

In practice I don't expect the UMA graphs to jump since DELETED_MESSAGES should
be very infrequent, but you'll see I added a comment to the histograms noting
when this changed.

+                            to_registered_app);
+      if (to_registered_app) {
+        UMA_HISTOGRAM_COUNTS("GCM.DataMessageReceived", 1);
+        UMA_HISTOGRAM_BOOLEAN("GCM.DataMessageReceivedHasCollapseKey",
+                              has_collapse_key);
+      }
+      break;
+    case GCMStatsRecorderImpl::DELETED_MESSAGES:
+      if (to_registered_app)
+        UMA_HISTOGRAM_COUNTS_1000("GCM.DeletedMessagesReceived", deleted_count);
+      break;
+  }
 
   base::TimeTicks new_timestamp = base::TimeTicks::Now();
   if (last_received_data_message_burst_start_time_.is_null()) {