Fix the DCHECK failure when starting and stopping GCMClient immediately

components/gcm_driver/gcm_client_impl.cc

 // 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.
 
 #include "components/gcm_driver/gcm_client_impl.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 484 matching lines @@
   // TODO(fgorski): This is one of the signals that store needs a rebuild.
   DCHECK(success);
 }
 
 void GCMClientImpl::UpdateRegistrationCallback(bool success) {
   // TODO(fgorski): This is one of the signals that store needs a rebuild.
   DCHECK(success);
 }
 
 void GCMClientImpl::Stop() {
+  weak_ptr_factory_.InvalidateWeakPtrs();
   device_checkin_info_.Reset();
   connection_factory_.reset();
   mcs_client_.reset();
   checkin_request_.reset();
   pending_registration_requests_.clear();
   state_ = INITIALIZED;
   gcm_store_->Close();
 }
 
 void GCMClientImpl::CheckOut() {
@@ skipping 353 matching lines @@
 
   recorder_.RecordIncomingSendError(
       data_message_stanza.category(),
       data_message_stanza.to(),
       data_message_stanza.id());
   delegate_->OnMessageSendError(data_message_stanza.category(),
                                 send_error_details);
 }
 
 }  // namespace gcm