Do not create GCM store if it is not needed

components/gcm_driver/gcm_client_impl.cc

 // 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.
 
 #include "components/gcm_driver/gcm_client_impl.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 343 matching lines @@
   // The delay start behavior will be abandoned when Start has been called
   // once with IMMEDIATE_START behavior.
   if (start_mode == IMMEDIATE_START)
     start_mode_ = IMMEDIATE_START;
 
   // Bail out if the loading is not started or completed.
   if (state_ != INITIALIZED)
     return;
 
   // Once the loading is completed, the check-in will be initiated.
-  gcm_store_->Load(base::Bind(&GCMClientImpl::OnLoadCompleted,
-                              weak_ptr_factory_.GetWeakPtr()));
+  // If we're in lazy start mode, don't create a new store since none is really
+  // using GCM functionality yet.
+  gcm_store_->Load(
+      (start_mode == IMMEDIATE_START) ?
+          GCMStore::CREATE_IF_MISSING :
+          GCMStore::DO_NOT_CREATE,
+      base::Bind(&GCMClientImpl::OnLoadCompleted,
+                 weak_ptr_factory_.GetWeakPtr()));
   state_ = LOADING;
 }
 
 void GCMClientImpl::OnLoadCompleted(scoped_ptr<GCMStore::LoadResult> result) {
   DCHECK_EQ(LOADING, state_);
 
   if (!result->success) {
-    ResetStore();
+    if (result->store_does_not_exist) {
+      // In the case that the store does not exist, set |state| back to
+      // INITIALIZED such that store loading could be triggered again when
+      // Start() is called with IMMEDIATE_START.
+      state_ = INITIALIZED;
+    } else {
+      // Otherwise, destroy the store to try again.
+      ResetStore();
+    }
     return;
   }
   gcm_store_reset_ = false;
 
   device_checkin_info_.android_id = result->device_android_id;
   device_checkin_info_.secret = result->device_security_token;
   device_checkin_info_.last_checkin_accounts = result->last_checkin_accounts;
   // A case where there were previously no accounts reported with checkin is
   // considered to be the same as when the list of accounts is empty. It enables
   // scheduling a periodic checkin for devices with no signed in users
@@ skipping 906 matching lines @@
 bool GCMClientImpl::HasStandaloneRegisteredApp() const {
   if (registrations_.empty())
     return false;
   // Note that account mapper is not counted as a standalone app since it is
   // automatically started when other app uses GCM.
   return registrations_.size() > 1 ||
          !ExistsGCMRegistrationInMap(registrations_, kGCMAccountMapperAppId);
 }
 
 }  // namespace gcm