WebRtcMediaStreamAdapter using WebRtcMediaStreamTrackMap.

content/renderer/media/rtc_peer_connection_handler.h

Index: content/renderer/media/rtc_peer_connection_handler.h
diff --git a/content/renderer/media/rtc_peer_connection_handler.h b/content/renderer/media/rtc_peer_connection_handler.h
index 14cb474a49d52bcf1a1a5ca626b903d5efa891f2..d0db835b5a19a58e42e099adccbc62db8883e7f6 100644
--- a/content/renderer/media/rtc_peer_connection_handler.h
+++ b/content/renderer/media/rtc_peer_connection_handler.h
@@ -21,6 +21,7 @@
 #include "base/threading/thread_checker.h"
 #include "content/common/content_export.h"
 #include "content/renderer/media/webrtc/media_stream_track_metrics.h"
+#include "content/renderer/media/webrtc/webrtc_media_stream_track_adapter_map.h"
 #include "ipc/ipc_platform_file.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
 #include "third_party/WebKit/public/platform/WebRTCPeerConnectionHandler.h"
@@ -260,6 +261,19 @@ class CONTENT_EXPORT RTCPeerConnectionHandler
 
   blink::WebFrame* frame_ = nullptr;
 
+  // Map and owners of track adapters. Every track that is in use by the peer
+  // connection has an associated blink and webrtc layer representation of it.
+  // The map keeps track of the relationship between
+  // |blink::WebMediaStreamTrack|s and |webrtc::MediaStreamTrackInterface|s.
+  // Track adapters are created on the fly when a component (such as a stream)
+  // needs to reference it, and automatically disposed when there are no longer
+  // any components referencing it.
+  scoped_refptr<WebRtcMediaStreamTrackAdapterMap> track_adapter_map_;
+  // Local stream adapters. Every stream that is in use by the peer connection
+  // has an associated blink and webrtc layer representation of it. This vector
+  // keeps track of the relationship between |blink::WebMediaStream|s and
+  // |webrtc::MediaStreamInterface|s. Streams are added and removed from the
+  // peer connection using |AddStream| and |RemoveStream|.
   std::vector<std::unique_ptr<WebRtcMediaStreamAdapter>> local_streams_;
 
   base::WeakPtr<PeerConnectionTracker> peer_connection_tracker_;