[GCM] Add heartbeat manager and reconnection logic due to heartbeat failure

google_apis/gcm/gcm.gyp

 # Copyright 2013 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
 
   'targets': [
@@ skipping 34 matching lines @@
         'base/socket_stream.h',
         'base/socket_stream.cc',
         'engine/connection_factory.h',
         'engine/connection_factory.cc',
         'engine/connection_factory_impl.h',
         'engine/connection_factory_impl.cc',
         'engine/connection_handler.h',
         'engine/connection_handler.cc',
         'engine/connection_handler_impl.h',
         'engine/connection_handler_impl.cc',
+        'engine/heartbeat_manager.h',
+        'engine/heartbeat_manager.cc',
         'engine/mcs_client.h',
         'engine/mcs_client.cc',
         'engine/rmq_store.h',
         'engine/rmq_store.cc',
         'gcm_client.cc',
         'gcm_client.h',
         'gcm_client_impl.cc',
         'gcm_client_impl.h',
         'protocol/mcs.proto',
       ],
@@ skipping 46 matching lines @@
       'sources': [
         'base/mcs_message_unittest.cc',
         'base/mcs_util_unittest.cc',
         'base/socket_stream_unittest.cc',
         'engine/connection_factory_impl_unittest.cc',
         'engine/connection_handler_impl_unittest.cc',
         'engine/fake_connection_factory.h',
         'engine/fake_connection_factory.cc',
         'engine/fake_connection_handler.h',
         'engine/fake_connection_handler.cc',
+        'engine/heartbeat_manager_unittest.cc',
         'engine/mcs_client_unittest.cc',
         'engine/rmq_store_unittest.cc',
       ]
     },
   ],
 }