Revert of [Media Router] Design MediaRouter interface with stub implementation.

chrome/browser/media/router/media_routes_observer.h

-// Copyright 2015 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.
-
-#ifndef CHROME_BROWSER_MEDIA_ROUTER_MEDIA_ROUTES_OBSERVER_H_
-#define CHROME_BROWSER_MEDIA_ROUTER_MEDIA_ROUTES_OBSERVER_H_
-
-#include <vector>
-
-#include "base/macros.h"
-#include "chrome/browser/media/router/media_route.h"
-
-namespace media_router {
-
-class MediaRouter;
-
-// Base class for observing when the set of MediaRoutes and their associated
-// MediaSinks have been updated.
-class MediaRoutesObserver {
- public:
-  explicit MediaRoutesObserver(MediaRouter* router);
-  virtual ~MediaRoutesObserver();
-
-  // This function is invoked when the list of routes and their associated
-  // sinks have been updated. Routes included in the list are created either
-  // locally or remotely.
-  virtual void OnRoutesUpdated(const std::vector<MediaRoute>& routes) {}
-
- private:
-  MediaRouter* router_;
-
-  DISALLOW_COPY_AND_ASSIGN(MediaRoutesObserver);
-};
-
-}  // namespace media_router
-
-#endif  // CHROME_BROWSER_MEDIA_ROUTER_MEDIA_ROUTES_OBSERVER_H_