Avoid toggling default receive streams in WebRtcVideoChannel2.

webrtc/media/engine/webrtcvideoengine2.h

 /*
  *  Copyright (c) 2014 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_MEDIA_ENGINE_WEBRTCVIDEOENGINE2_H_
 #define WEBRTC_MEDIA_ENGINE_WEBRTCVIDEOENGINE2_H_
 
 #include <map>
 #include <memory>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "webrtc/api/call/transport.h"
 #include "webrtc/api/video/video_frame.h"
 #include "webrtc/base/asyncinvoker.h"
 #include "webrtc/base/criticalsection.h"
 #include "webrtc/base/networkroute.h"
+#include "webrtc/base/optional.h"
 #include "webrtc/base/thread_annotations.h"
 #include "webrtc/base/thread_checker.h"
-#include "webrtc/media/base/videosinkinterface.h"
-#include "webrtc/media/base/videosourceinterface.h"
 #include "webrtc/call/call.h"
 #include "webrtc/call/flexfec_receive_stream.h"
 #include "webrtc/media/base/mediaengine.h"
+#include "webrtc/media/base/videosinkinterface.h"
+#include "webrtc/media/base/videosourceinterface.h"
 #include "webrtc/media/engine/webrtcvideodecoderfactory.h"
 #include "webrtc/media/engine/webrtcvideoencoderfactory.h"
 #include "webrtc/video_receive_stream.h"
 #include "webrtc/video_send_stream.h"
 
 namespace webrtc {
 class VideoDecoder;
 class VideoEncoder;
 struct MediaConfig;
 }
@@ skipping 32 matching lines @@
 };
 
 // TODO(pbos): Remove, use external handlers only.
 class DefaultUnsignalledSsrcHandler : public UnsignalledSsrcHandler {
  public:
   DefaultUnsignalledSsrcHandler();
   Action OnUnsignalledSsrc(WebRtcVideoChannel2* channel,
                            uint32_t ssrc) override;
 
   rtc::VideoSinkInterface<webrtc::VideoFrame>* GetDefaultSink() const;
-  void SetDefaultSink(VideoMediaChannel* channel,
+  void SetDefaultSink(WebRtcVideoChannel2* channel,
                       rtc::VideoSinkInterface<webrtc::VideoFrame>* sink);
 
-  uint32_t default_recv_ssrc() const { return default_recv_ssrc_; }
-
   virtual ~DefaultUnsignalledSsrcHandler() = default;
 
  private:
-  uint32_t default_recv_ssrc_;
   rtc::VideoSinkInterface<webrtc::VideoFrame>* default_sink_;
 };
 
 // WebRtcVideoEngine2 is used for the new native WebRTC Video API (webrtc:1667).
 class WebRtcVideoEngine2 {
  public:
   WebRtcVideoEngine2();
   virtual ~WebRtcVideoEngine2();
 
   // Basic video engine implementation.
@@ skipping 67 matching lines @@
                       const rtc::PacketTime& packet_time) override;
   void OnReadyToSend(bool ready) override;
   void OnNetworkRouteChanged(const std::string& transport_name,
                              const rtc::NetworkRoute& network_route) override;
   void OnTransportOverheadChanged(int transport_overhead_per_packet) override;
   void SetInterface(NetworkInterface* iface) override;
 
   // Implemented for VideoMediaChannelTest.
   bool sending() const { return sending_; }
 
+  rtc::Optional<uint32_t> GetDefaultReceiveStreamSsrc();
+
   // AdaptReason is used for expressing why a WebRtcVideoSendStream request
   // a lower input frame size than the currently configured camera input frame
   // size. There can be more than one reason OR:ed together.
   enum AdaptReason {
     ADAPTREASON_NONE = 0,
     ADAPTREASON_CPU = 1,
     ADAPTREASON_BANDWIDTH = 2,
   };
 
  private:
@@ skipping 311 matching lines @@
   // send_params/recv_params, rtp_extensions, options, etc.
   VideoSendParameters send_params_;
   VideoOptions default_send_options_;
   VideoRecvParameters recv_params_;
   int64_t last_stats_log_ms_;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_MEDIA_ENGINE_WEBRTCVIDEOENGINE2_H_