[GCM] Fix mcs_probe credential handling

google_apis/gcm/engine/mcs_client.cc

Index: google_apis/gcm/engine/mcs_client.cc
diff --git a/google_apis/gcm/engine/mcs_client.cc b/google_apis/gcm/engine/mcs_client.cc
index 5e6490ac2d3ec497ec20d680d267bb15f042ab52..726ff32e58f6f3fa22419f4f176f78e90013aa7c 100644
--- a/google_apis/gcm/engine/mcs_client.cc
+++ b/google_apis/gcm/engine/mcs_client.cc
@@ -204,9 +204,10 @@ void MCSClient::Login(uint64 android_id, uint64 security_token) {
     security_token_ = security_token;
   }
 
+  DCHECK(android_id_ != 0 || restored_unackeds_server_ids_.empty());
+
   state_ = CONNECTING;
   connection_factory_->Connect();
-  DCHECK(restored_unackeds_server_ids_.empty());
 }
 
 void MCSClient::SendMessage(const MCSMessage& message) {