components: Introduce AlarmTimer class and use it for GCM heartbeat

base/timer/timer.h

Index: base/timer/timer.h
diff --git a/base/timer/timer.h b/base/timer/timer.h
index 6d282ee8e7ac84f3d6f5757650c08be70463f9e6..b96b3c145b1372a7f4bd41bd87499dd9c02eb745 100644
--- a/base/timer/timer.h
+++ b/base/timer/timer.h
@@ -111,9 +111,16 @@ class BASE_EXPORT Timer {
                    TimeDelta delay,
                    const base::Closure& user_task);
 
+  void set_user_task(const Closure& task) { user_task_ = task; }
+  void set_desired_run_time(TimeTicks desired) { desired_run_time_ = desired; }
+  void set_is_running(bool running) { is_running_ = running; }
+
+  const tracked_objects::Location& posted_from() { return posted_from_; }

[Lei Zhang, 2014/10/24 00:44:49]

this can be a const method, same for is_running().

[Chirantan Ekbote, 2014/10/24 01:04:13]

Done.

+
   bool retain_user_task() const { return retain_user_task_; }
   bool is_repeating() const { return is_repeating_; }
 
+  bool is_running() { return is_running_; }

[Lei Zhang, 2014/10/24 00:44:49]

nit: group with the other getters, and put blank line above private:

[Chirantan Ekbote, 2014/10/24 01:04:13]

Done.

  private:
   friend class BaseTimerTaskInternal;