Do not create GCM store if it is not needed

google_apis/gcm/engine/gcm_store_impl.h

 // 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.
 
 #ifndef GOOGLE_APIS_GCM_ENGINE_GCM_STORE_IMPL_H_
 #define GOOGLE_APIS_GCM_ENGINE_GCM_STORE_IMPL_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 13 matching lines @@
 // It performs all blocking operations on the blocking task runner, and posts
 // all callbacks to the thread on which the GCMStoreImpl is created.
 class GCM_EXPORT GCMStoreImpl : public GCMStore {
  public:
   GCMStoreImpl(const base::FilePath& path,
                scoped_refptr<base::SequencedTaskRunner> blocking_task_runner,
                scoped_ptr<Encryptor> encryptor);
   ~GCMStoreImpl() override;
 
   // Load the directory and pass the initial state back to caller.
-  void Load(const LoadCallback& callback) override;
+  void Load(StoreOpenMode open_mode, const LoadCallback& callback) override;
 
   // Closes the GCM store.
   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
   // and require the device to re-create credentials and serial number mapping
   // tables.
   void Destroy(const UpdateCallback& callback) override;
@@ skipping 100 matching lines @@
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
 
   base::WeakPtrFactory<GCMStoreImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GCMStoreImpl);
 };
 
 }  // namespace gcm
 
 #endif  // GOOGLE_APIS_GCM_ENGINE_GCM_STORE_IMPL_H_