Ash: Support "Next Song", "Previous Song", "Play/Pause" Multi Media buttons

ash/test/test_shell_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_shell_delegate.h"
 
 #include <algorithm>
 
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
@@ skipping 100 matching lines @@
 aura::client::UserActionClient* TestShellDelegate::CreateUserActionClient() {
   return NULL;
 }
 
 void TestShellDelegate::OpenFeedbackPage() {
 }
 
 void TestShellDelegate::RecordUserMetricsAction(UserMetricsAction action) {
 }
 
+void TestShellDelegate::HandleMediaNextTrack() {
+}
+
+void TestShellDelegate::HandleMediaPlayPause() {
+}
+
+void TestShellDelegate::HandleMediaPrevTrack() {
+}
+
 }  // namespace test
 }  // namespace ash