Move EmptyString, kWhitespace and the BOM to base.

ash/test/test_launcher_delegate.cc

 // Copyright (c) 2012 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 "ash/test/test_launcher_delegate.h"
 
 #include "ash/launcher/launcher_item_delegate_manager.h"
 #include "ash/shelf/shelf_model.h"
 #include "ash/shelf/shelf_util.h"
 #include "ash/shell.h"
@@ skipping 72 matching lines @@
 
 void TestLauncherDelegate::OnLauncherDestroyed(Launcher* launcher) {
 }
 
 LauncherID TestLauncherDelegate::GetLauncherIDForAppID(
     const std::string& app_id) {
   return 0;
 }
 
 const std::string& TestLauncherDelegate::GetAppIDForLauncherID(LauncherID id) {
-  return EmptyString();
+  return base::EmptyString();
 }
 
 void TestLauncherDelegate::PinAppWithID(const std::string& app_id) {
 }
 
 bool TestLauncherDelegate::CanPin() const {
   return true;
 }
 
 bool TestLauncherDelegate::IsAppPinned(const std::string& app_id) {
   return false;
 }
 
 void TestLauncherDelegate::UnpinAppWithID(const std::string& app_id) {
 }
 
 }  // namespace test
 }  // namespace ash