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

google_apis/gcm/engine/gcm_store_impl.h

Index: google_apis/gcm/engine/gcm_store_impl.h
diff --git a/google_apis/gcm/engine/gcm_store_impl.h b/google_apis/gcm/engine/gcm_store_impl.h
index b8550dabe179165cf5bd037a8fd9b6f0729d16c2..88ed164c7da74666dbe68be0d347b19d1cfd0857 100644
--- a/google_apis/gcm/engine/gcm_store_impl.h
+++ b/google_apis/gcm/engine/gcm_store_impl.h
@@ -31,6 +31,9 @@ class GCM_EXPORT GCMStoreImpl : public GCMStore {
   // Load the directory and pass the initial state back to caller.
   virtual void Load(const LoadCallback& callback) OVERRIDE;
 
+  // Closes the GCM store.
+  virtual void Close() OVERRIDE;
+
   // Clears the GCM store of all data and destroys any LevelDB files associated
   // with this store.
   // WARNING: this will permanently destroy any pending outgoing messages