[GCM] Stop/restart GCM when the state is forced off/on

google_apis/gcm/gcm_client_impl.cc

Index: google_apis/gcm/gcm_client_impl.cc
diff --git a/google_apis/gcm/gcm_client_impl.cc b/google_apis/gcm/gcm_client_impl.cc
index 640977afb806f28efd0624d4a181f0d7495b2a5c..aa12ee88a925f8c13bc2976b4edd2c974e996fc3 100644
--- a/google_apis/gcm/gcm_client_impl.cc
+++ b/google_apis/gcm/gcm_client_impl.cc
@@ -286,14 +286,19 @@ void GCMClientImpl::SetDeviceCredentialsCallback(bool success) {
   DCHECK(success);
 }
 
-void GCMClientImpl::CheckOut() {
+void GCMClientImpl::Stop() {
   device_checkin_info_.Reset();
   mcs_client_.reset();
-  gcm_store_->Destroy(base::Bind(&GCMClientImpl::OnGCMStoreDestroyed,
-                                 weak_ptr_factory_.GetWeakPtr()));
   checkin_request_.reset();
   pending_registrations_.clear();
   state_ = INITIALIZED;
+  gcm_store_->Close();
+}
+
+void GCMClientImpl::CheckOut() {
+  Stop();
+  gcm_store_->Destroy(base::Bind(&GCMClientImpl::OnGCMStoreDestroyed,
+                                 weak_ptr_factory_.GetWeakPtr()));
 }
 
 void GCMClientImpl::Register(const std::string& app_id,