Link GCM heartbeat with wake on wifi preference

components/timers/alarm_timer.h

Index: components/timers/alarm_timer.h
diff --git a/components/timers/alarm_timer.h b/components/timers/alarm_timer.h
index 80bc45b3af4dfc2c9f04180a5e5a4c11c6384cb3..d2f93335d61c518c4516b523b94058df949a1577 100644
--- a/components/timers/alarm_timer.h
+++ b/components/timers/alarm_timer.h
@@ -61,7 +61,11 @@ class AlarmTimer : public base::Timer,
 
   ~AlarmTimer() override;
 
-  bool can_wake_from_suspend() { return can_wake_from_suspend_; }
+  bool can_wake_from_suspend() const { return can_wake_from_suspend_; }
+
+  // Must be called by the delegate to indicate that the timer has fired and
+  // that the user task should be run.
+  void OnTimerFired();
 
   // Timer overrides.
   void Stop() override;
@@ -70,10 +74,6 @@ class AlarmTimer : public base::Timer,
   // MessageLoop::DestructionObserver overrides.
   void WillDestroyCurrentMessageLoop() override;
 
-  // Must be called by the delegate to indicate that the timer has fired and
-  // that the user task should be run.
-  void OnTimerFired();
-
  private:
   // Initializes the timer with the appropriate delegate.
   void Init();