[GCM] Add app handler support for connection events

components/gcm_driver/gcm_driver.h

Index: components/gcm_driver/gcm_driver.h
diff --git a/components/gcm_driver/gcm_driver.h b/components/gcm_driver/gcm_driver.h
index e2fe882532c28d68fd2494c96387cebb949af421..a215abddf6ce6f67e87379baa191c95d9c84931e 100644
--- a/components/gcm_driver/gcm_driver.h
+++ b/components/gcm_driver/gcm_driver.h
@@ -86,6 +86,9 @@ class GCMDriver {
   // Returns true if the gcm client is ready.
   virtual bool IsGCMClientReady() const = 0;
 
+  // Returns true if the gcm client has an open and active connection.
+  virtual bool IsConnected() const = 0;
+
   // Get GCM client internal states and statistics.
   // If clear_logs is true then activity logs will be cleared before the stats
   // are returned.