Record latencies of connection and arrival of first message in UMA

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 0fd6fb3d411d263593af3c77cc4f2ba171401a59..96a6228a91f94fdd7d6e022c367cf28922f9bbc2 100644
--- a/components/gcm_driver/gcm_stats_recorder_impl.cc
+++ b/components/gcm_driver/gcm_stats_recorder_impl.cc
@@ -143,7 +143,8 @@ std::string GetUnregistrationStatusString(
 
 GCMStatsRecorderImpl::GCMStatsRecorderImpl()
     : is_recording_(false),
-      delegate_(NULL) {
+      delegate_(NULL),
+      data_message_received_since_connected_(false) {
 }
 
 GCMStatsRecorderImpl::~GCMStatsRecorderImpl() {
@@ -224,6 +225,8 @@ void GCMStatsRecorderImpl::RecordConnection(
 }
 
 void GCMStatsRecorderImpl::RecordConnectionInitiated(const std::string& host) {
+  last_connection_initiation_time_ = base::Time::Now();

[fgorski, 2014/07/22 04:08:36]

make sure last_connection_success_time_ is null for the DCHECK in 388 to make
sense more than once.

[juyik, 2014/07/22 17:51:20]

Done.

+  data_message_received_since_connected_ = false;
   if (!is_recording_)
     return;
   RecordConnection("Connection initiated", host);
@@ -239,6 +242,11 @@ void GCMStatsRecorderImpl::RecordConnectionDelayedDueToBackoff(
 }
 
 void GCMStatsRecorderImpl::RecordConnectionSuccess() {
+  DCHECK(!last_connection_initiation_time_.is_null());
+  UMA_HISTOGRAM_COUNTS(
+      "GCM.ConnectionLatency",
+      (base::Time::Now() - last_connection_initiation_time_).InMilliseconds());
+  last_connection_success_time_ = base::Time::Now();

[fgorski, 2014/07/22 04:08:36]

make sure last_connection_initiation_time_ is set to null here for the dcheck in
245 to make sense more than one.

[juyik, 2014/07/22 17:51:20]

Done.

   if (!is_recording_)
     return;
   RecordConnection("Connection succeeded", std::string());
@@ -376,6 +384,13 @@ void GCMStatsRecorderImpl::RecordDataMessageReceived(
             .InSeconds());
     last_received_data_message_burst_start_time_ = new_timestamp;
   }
+  if (!data_message_received_since_connected_) {
+    DCHECK(!last_connection_success_time_.is_null());
+    UMA_HISTOGRAM_COUNTS(
+        "GCM.FirstReceivedDataMessageLatencyAfterConnection",
+        (new_timestamp - last_connection_success_time_).InMilliseconds());
+    data_message_received_since_connected_ = true;
+  }
 
   if (!is_recording_)
     return;