Move talk/app/webrtc to webrtc/api

webrtc/api/mediastreamobserver.h

+/*
+ *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_API_MEDIASTREAMOBSERVER_H_
+#define WEBRTC_API_MEDIASTREAMOBSERVER_H_
+
+#include "webrtc/api/mediastreaminterface.h"
+#include "webrtc/base/scoped_ref_ptr.h"
+#include "webrtc/base/sigslot.h"
+
+namespace webrtc {
+
+// Helper class which will listen for changes to a stream and emit the
+// corresponding signals.
+class MediaStreamObserver : public ObserverInterface {
+ public:
+  explicit MediaStreamObserver(MediaStreamInterface* stream);
+  ~MediaStreamObserver();
+
+  const MediaStreamInterface* stream() const { return stream_; }
+
+  void OnChanged() override;
+
+  sigslot::signal2<AudioTrackInterface*, MediaStreamInterface*>
+      SignalAudioTrackAdded;
+  sigslot::signal2<AudioTrackInterface*, MediaStreamInterface*>
+      SignalAudioTrackRemoved;
+  sigslot::signal2<VideoTrackInterface*, MediaStreamInterface*>
+      SignalVideoTrackAdded;
+  sigslot::signal2<VideoTrackInterface*, MediaStreamInterface*>
+      SignalVideoTrackRemoved;
+
+ private:
+  rtc::scoped_refptr<MediaStreamInterface> stream_;
+  AudioTrackVector cached_audio_tracks_;
+  VideoTrackVector cached_video_tracks_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_API_MEDIASTREAMOBSERVER_H_