Add media router common classes and unittests.

chrome/browser/media/router/media_controller_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 "chrome/browser/media/router/media_controller_impl.h"
+
+namespace media_router {
+
+MediaControllerImpl::MediaControllerImpl(const MediaRouteId& media_route_id)
+    : MediaController(media_route_id) {}
+
+MediaControllerImpl::~MediaControllerImpl() {
+}
+
+// TODO(imcheng): Implement the following.
+void MediaControllerImpl::Pause() {
+}
+
+void MediaControllerImpl::Resume() {
+}
+
+void MediaControllerImpl::Play() {
+}
+
+void MediaControllerImpl::Stop() {
+}
+
+void MediaControllerImpl::Next() {
+}
+
+void MediaControllerImpl::Previous() {
+}
+
+void MediaControllerImpl::SeekRelative(double seek_seconds) {
+}
+
+void MediaControllerImpl::SeekAbsolute(double seek_seconds) {
+}
+
+void MediaControllerImpl::VolumeUp() {
+}
+
+void MediaControllerImpl::VolumeDown() {
+}
+
+void MediaControllerImpl::Mute() {
+}
+
+void MediaControllerImpl::Unmute() {
+}
+
+}  // namespace media_router