Add media router common classes and unittests.

chrome/browser/media/router/media_controller.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.h"
+
+namespace media_router {
+
+MediaController::MediaController(const MediaRouteId& media_route_id)
+    : media_route_id_(media_route_id),
+      media_controls_capabilities_(0),
+      media_status_(media_route_id) {}
+
+MediaController::~MediaController() {
+}
+
+void MediaController::AddObserver(MediaController::Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void MediaController::RemoveObserver(MediaController::Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+bool MediaController::SupportsCommand(MediaCommand command) const {
+  return (media_controls_capabilities_ & command) > 0;
+}
+
+void MediaController::set_media_status(const MediaStatus& status) {
+  if (media_status_ != status) {
+    media_status_ = status;
+    FOR_EACH_OBSERVER(MediaController::Observer, observers_,
+        OnMediaStatusChange(this, status));
+  }
+}
+
+void MediaController::set_media_controls_capabilities(
+    MediaControlsCapabilities capabilities) {
+  if (media_controls_capabilities_ != capabilities) {
+    media_controls_capabilities_ = capabilities;
+    FOR_EACH_OBSERVER(MediaController::Observer, observers_,
+        OnMediaControlsCapabilitiesChange(this, capabilities));
+  }
+}
+
+}  // namespace media_router