Add PeerConnection IsClosed check.

webrtc/api/webrtcsession.cc

Index: webrtc/api/webrtcsession.cc
diff --git a/webrtc/api/webrtcsession.cc b/webrtc/api/webrtcsession.cc
index b9a3fc8453389dc040a28f51a47d0a4649e0eb49..4bc8b5fe46b8aaeeb277a0d786a2b151ec2ef91a 100644
--- a/webrtc/api/webrtcsession.cc
+++ b/webrtc/api/webrtcsession.cc
@@ -453,20 +453,20 @@ bool CheckForRemoteIceRestart(const SessionDescriptionInterface* old_desc,
   return false;
 }
 
-WebRtcSession::WebRtcSession(webrtc::MediaControllerInterface* media_controller,
-                             rtc::Thread* network_thread,
-                             rtc::Thread* worker_thread,
-                             rtc::Thread* signaling_thread,
-                             cricket::PortAllocator* port_allocator)
+WebRtcSession::WebRtcSession(
+    webrtc::MediaControllerInterface* media_controller,
+    rtc::Thread* network_thread,
+    rtc::Thread* worker_thread,
+    rtc::Thread* signaling_thread,
+    cricket::PortAllocator* port_allocator,
+    std::unique_ptr<cricket::TransportController> transport_controller)
     : worker_thread_(worker_thread),
       signaling_thread_(signaling_thread),
       // RFC 3264: The numeric value of the session id and version in the
       // o line MUST be representable with a "64 bit signed integer".
       // Due to this constraint session id |sid_| is max limited to LLONG_MAX.
       sid_(rtc::ToString(rtc::CreateRandomId64() & LLONG_MAX)),
-      transport_controller_(new cricket::TransportController(signaling_thread,
-                                                             network_thread,
-                                                             port_allocator)),
+      transport_controller_(std::move(transport_controller)),
       media_controller_(media_controller),
       channel_manager_(media_controller_->channel_manager()),
       ice_observer_(NULL),