RTCRtpSender with track behind RuntimeEnabled flag

content/shell/test_runner/mock_webrtc_peer_connection_handler.h

Index: content/shell/test_runner/mock_webrtc_peer_connection_handler.h
diff --git a/content/shell/test_runner/mock_webrtc_peer_connection_handler.h b/content/shell/test_runner/mock_webrtc_peer_connection_handler.h
index e1ceca8d6aaf956883c66c6a8ce44e93c7cb9131..415bee2108aac7942f663755287cdcb1fb11f040 100644
--- a/content/shell/test_runner/mock_webrtc_peer_connection_handler.h
+++ b/content/shell/test_runner/mock_webrtc_peer_connection_handler.h
@@ -61,6 +61,8 @@ class MockWebRTCPeerConnectionHandler
   void RemoveStream(const blink::WebMediaStream& stream) override;
   void GetStats(const blink::WebRTCStatsRequest& request) override;
   void GetStats(std::unique_ptr<blink::WebRTCStatsReportCallback>) override;
+  blink::WebVector<std::unique_ptr<blink::WebRTCRtpSender>> GetSenders()
+      override;
   blink::WebVector<std::unique_ptr<blink::WebRTCRtpReceiver>> GetReceivers()
       override;
   blink::WebRTCDataChannelHandler* CreateDataChannel(
@@ -99,7 +101,7 @@ class MockWebRTCPeerConnectionHandler
   typedef std::map<std::string, blink::WebMediaStream> StreamMap;
   StreamMap local_streams_;
   StreamMap remote_streams_;
-  std::map<std::string, uintptr_t> receiver_id_by_track_;
+  std::map<std::string, uintptr_t> id_by_track_;
 
   base::WeakPtrFactory<MockWebRTCPeerConnectionHandler> weak_factory_;