[GCM] Remove all persisted data and close connections when signing out of a profile

google_apis/gcm/engine/mcs_client.h

Index: google_apis/gcm/engine/mcs_client.h
diff --git a/google_apis/gcm/engine/mcs_client.h b/google_apis/gcm/engine/mcs_client.h
index 036acb8b159f2079b2f3818e3cef2296ebae274e..d7bd71bef87039b265f97ca8d9678872ee5d9ff5 100644
--- a/google_apis/gcm/engine/mcs_client.h
+++ b/google_apis/gcm/engine/mcs_client.h
@@ -123,6 +123,8 @@ class GCM_EXPORT MCSClient {
   // Disconnects the client and permanently destroys the persistent GCM store.
   // WARNING: This is permanent, and the client must be recreated with new
   // credentials afterwards.
+  // TODO(jianli): destroying the persistent GCM store should be moved to
+  // GCMClient.
   void Destroy();
 
   // Returns the current state of the client.