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

chrome/browser/media/router/media_sinks_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_SINKS_OBSERVER_H_
-#define CHROME_BROWSER_MEDIA_ROUTER_MEDIA_SINKS_OBSERVER_H_
-
-#include <vector>
-
-#include "base/macros.h"
-#include "chrome/browser/media/router/media_sink.h"
-#include "chrome/browser/media/router/media_source.h"
-
-namespace media_router {
-
-class MediaRouter;
-
-// Base class for observing when the collection of sinks compatible with
-// a MediaSource has been updated.
-// A MediaSinksObserver implementation can be registered to MediaRouter to
-// receive results. It can then interpret / process the results accordingly.
-class MediaSinksObserver {
- public:
-  // Constructs an observer that will observe for sinks compatible
-  // with |source|.
-  MediaSinksObserver(MediaRouter* router, const MediaSource& source);
-  virtual ~MediaSinksObserver();
-
-  // This function is invoked when the list of sinks compatible
-  // with |source_| has been updated.
-  virtual void OnSinksReceived(const std::vector<MediaSink>& sinks) {}
-
-  const MediaSource& source() const { return source_; }
-
- private:
-  const MediaSource source_;
-  MediaRouter* router_;
-
-  DISALLOW_COPY_AND_ASSIGN(MediaSinksObserver);
-};
-
-}  // namespace media_router
-
-#endif  // CHROME_BROWSER_MEDIA_ROUTER_MEDIA_SINKS_OBSERVER_H_