[GCM] Be more aggressive about triggering heartbeats when waking from sleep

google_apis/gcm/engine/heartbeat_manager.h

Index: google_apis/gcm/engine/heartbeat_manager.h
diff --git a/google_apis/gcm/engine/heartbeat_manager.h b/google_apis/gcm/engine/heartbeat_manager.h
index a6d47ea241f2cecc4958875e04ac336730832ddc..83a25cfda5271e24a898547782c736752d2ee0e6 100644
--- a/google_apis/gcm/engine/heartbeat_manager.h
+++ b/google_apis/gcm/engine/heartbeat_manager.h
@@ -61,6 +61,7 @@ class GCM_EXPORT HeartbeatManager : public base::PowerObserver {
   void UpdateHeartbeatTimer(scoped_ptr<base::Timer> timer);
 
   // base::PowerObserver override.
+  void OnSuspend() override;
   void OnResume() override;
 
   // Maximum and minimum of the custom client interval that can be requested,
@@ -114,6 +115,9 @@ class GCM_EXPORT HeartbeatManager : public base::PowerObserver {
   // Timer for triggering heartbeats.
   scoped_ptr<base::Timer> heartbeat_timer_;
 
+  // Time at which the machine was last suspended.
+  base::Time suspend_time_;
+
   // Callbacks for interacting with the the connection.
   base::Closure send_heartbeat_callback_;
   ReconnectCallback trigger_reconnect_callback_;