Implement local storage for App List in case app sync is off.

chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl_unittest.cc

 // Copyright 2013 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 "chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <map>
@@ skipping 3997 matching lines @@
       app_service_->GetPinPosition(extension_misc::kChromeAppId)));
   EXPECT_TRUE(
       position_1.Equals(app_service_->GetPinPosition(extension1_->id())));
   EXPECT_TRUE(
       position_1.Equals(app_service_->GetPinPosition(extension1_->id())));
   EXPECT_TRUE(
       position_2.Equals(app_service_->GetPinPosition(extension2_->id())));
   EXPECT_TRUE(
       position_3.Equals(app_service_->GetPinPosition(extension3_->id())));
 }
+
+// Test the case when sync app is turned off and we need to use local copy to
+// support user's pins.
+TEST_F(ChromeLauncherControllerImplTest, SyncOffLocalUpdate) {
+  InitLauncherController();
+
+  extension_service_->AddExtension(extension1_.get());
+  extension_service_->AddExtension(extension2_.get());
+
+  syncer::SyncChangeList sync_list;
+  InsertAddPinChange(&sync_list, 0, extension_misc::kChromeAppId);
+  InsertAddPinChange(&sync_list, 1, extension1_->id());
+  InsertAddPinChange(&sync_list, 1, extension2_->id());
+  SendPinChanges(sync_list, true);
+
+  EXPECT_EQ("AppList, Chrome, App1, App2", GetPinnedAppStatus());
+
+  syncer::SyncDataList copy_sync_list =
+      app_service_->GetAllSyncData(syncer::APP_LIST);
+
+  app_service_->StopSyncing(syncer::APP_LIST);
+  RecreateChromeLauncher();
+
+  // Pinned state should not change.
+  EXPECT_EQ("AppList, Chrome, App1, App2", GetPinnedAppStatus());
+  launcher_controller_->UnpinAppWithID(extension2_->id());
+  EXPECT_EQ("AppList, Chrome, App1", GetPinnedAppStatus());
+
+  // Resume syncing and sync information overrides local copy.
+  StartAppSyncService(copy_sync_list);
+  EXPECT_EQ("AppList, Chrome, App1, App2", GetPinnedAppStatus());
+}