Track pending ICE restarts independently for different media sections.

talk/app/webrtc/webrtcsession.h

Index: talk/app/webrtc/webrtcsession.h
diff --git a/talk/app/webrtc/webrtcsession.h b/talk/app/webrtc/webrtcsession.h
index 9695de65d3c03df4d6767ef02383fefec01c5f51..5ce6b4d7d9c3fbabecaf0b1be5a5da2a2345dd40 100644
--- a/talk/app/webrtc/webrtcsession.h
+++ b/talk/app/webrtc/webrtcsession.h
@@ -301,9 +301,11 @@ class WebRtcSession : public AudioProviderInterface,
 
   cricket::DataChannelType data_channel_type() const;
 
-  bool IceRestartPending() const;
-
-  void ResetIceRestartLatch();
+  // TODO(deadbeef): Replace these with:
+  // bool IceRestartPending(const std::string& mid) const;

[honghaiz3, 2016/02/10 01:01:48]

Does this need a lot of work?
If not, maybe it can be done in this CL. 

[Taylor Brandstetter, 2016/02/10 21:18:32]

I couldn't do this before because there was an issue with mids not matching up
between successive offer/answer exchanges. But since that's fixed, I went ahead
and did the necessary refactoring.

+  bool AudioIceRestartPending() const;
+  bool VideoIceRestartPending() const;
+  bool DataIceRestartPending() const;
 
   // Called when an RTCCertificate is generated or retrieved by
   // WebRTCSessionDescriptionFactory. Should happen before setLocalDescription.
@@ -503,7 +505,9 @@ class WebRtcSession : public AudioProviderInterface,
   // 2. If constraint kEnableRtpDataChannels is true, RTP is allowed (DCT_RTP);
   // 3. If both 1&2 are false, data channel is not allowed (DCT_NONE).
   cricket::DataChannelType data_channel_type_;
-  rtc::scoped_ptr<IceRestartAnswerLatch> ice_restart_latch_;
+  rtc::scoped_ptr<IceRestartAnswerLatch> audio_ice_restart_latch_;
+  rtc::scoped_ptr<IceRestartAnswerLatch> video_ice_restart_latch_;
+  rtc::scoped_ptr<IceRestartAnswerLatch> data_ice_restart_latch_;
 
   rtc::scoped_ptr<WebRtcSessionDescriptionFactory>
       webrtc_session_desc_factory_;