Fix for data channels perpetually stuck in "closing" state.

webrtc/api/datachannel.cc

Index: webrtc/api/datachannel.cc
diff --git a/webrtc/api/datachannel.cc b/webrtc/api/datachannel.cc
index 5bffa03ce96db05c16cf3a99b1c3a7e1c4736793..6b13bf2c705ae7152c9ce4fa6edef00f9ce92340 100644
--- a/webrtc/api/datachannel.cc
+++ b/webrtc/api/datachannel.cc
@@ -297,10 +297,11 @@ void DataChannel::OnTransportChannelCreated() {
   }
 }
 
-// The underlying transport channel was destroyed.
-// This function makes sure the DataChannel is disconnected and changes state to
-// kClosed.
 void DataChannel::OnTransportChannelDestroyed() {
+  // This method needs to synchronously close the data channel, which means any
+  // queued data needs to be discarded.
+  queued_send_data_.Clear();
+  queued_control_data_.Clear();
   DoClose();
 }