components: Introduce AlarmTimer class and use it for GCM heartbeat

google_apis/gcm/engine/heartbeat_manager.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GOOGLE_APIS_GCM_ENGINE_HEARTBEAT_MANAGER_H_
 #define GOOGLE_APIS_GCM_ENGINE_HEARTBEAT_MANAGER_H_
 
 #include "base/callback.h"
 #include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
-#include "base/timer/timer.h"
 #include "google_apis/gcm/base/gcm_export.h"
 
+namespace base {
+class Timer;
+}
+
 namespace mcs_proto {
 class HeartbeatConfig;
 }
 
 namespace gcm {
 
 // A heartbeat management class, capable of sending and handling heartbeat
 // receipt/failures and triggering reconnection as necessary.
 class GCM_EXPORT HeartbeatManager {
  public:
@@ skipping 34 matching lines @@
 
   // Whether the last heartbeat ping sent has been acknowledged or not.
   bool waiting_for_ack_;
 
   // The current heartbeat interval.
   int heartbeat_interval_ms_;
   // The most recent server-provided heartbeat interval (0 if none has been
   // provided).
   int server_interval_ms_;
 
-  // Timer for triggering heartbeats.
-  base::Timer heartbeat_timer_;
+  // Timer for triggering heartbeats.  Owned by HeartbeatManager.

[Nicolas Zea, 2014/10/21 17:57:54]

nit: Since you're using a scoped_ptr now, ownership is implied. No need for the
comment.

[Chirantan Ekbote, 2014/10/21 21:13:48]

Done.

+  scoped_ptr<base::Timer> heartbeat_timer_;
 
   // Callbacks for interacting with the the connection.
   base::Closure send_heartbeat_callback_;
   base::Closure trigger_reconnect_callback_;
 
   base::WeakPtrFactory<HeartbeatManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HeartbeatManager);
 };
 
 }  // namespace gcm
 
 #endif  // GOOGLE_APIS_GCM_ENGINE_HEARTBEAT_MANAGER_H_