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

ash/test/test_shell_delegate.cc

Index: ash/test/test_shell_delegate.cc
diff --git a/ash/test/test_shell_delegate.cc b/ash/test/test_shell_delegate.cc
index 090d14a1321e8d0012b9763d3cf5e4f8c317d8a0..3ecb75a2f20a9a9bd8d5d3df1b9d3cfb186d666c 100644
--- a/ash/test/test_shell_delegate.cc
+++ b/ash/test/test_shell_delegate.cc
@@ -118,5 +118,14 @@ void TestShellDelegate::OpenFeedbackPage() {
 void TestShellDelegate::RecordUserMetricsAction(UserMetricsAction action) {
 }
 
+void TestShellDelegate::HandleMediaNextTrack() {
+}
+
+void TestShellDelegate::HandleMediaPlayPause() {
+}
+
+void TestShellDelegate::HandleMediaPrevTrack() {
+}
+
 }  // namespace test
 }  // namespace ash