Stop processing any incoming packets when turn port is disconnected.

webrtc/p2p/base/turnport.cc

Index: webrtc/p2p/base/turnport.cc
diff --git a/webrtc/p2p/base/turnport.cc b/webrtc/p2p/base/turnport.cc
index 5ed93dd1d84a05b445aeaeeeed47b3ab26172c3d..4f5fef1d53ffcd90c7b191ee7a88146c1e17f951 100644
--- a/webrtc/p2p/base/turnport.cc
+++ b/webrtc/p2p/base/turnport.cc
@@ -555,6 +555,12 @@ void TurnPort::OnReadPacket(
     return;
   }
 
+  if (state_ == STATE_DISCONNECTED) {
+    LOG_J(LS_WARNING, this)
+        << "Received TURN message while the Turn port is disconnected";
+    return;
+  }
+
   // Check the message type, to see if is a Channel Data message.
   // The message will either be channel data, a TURN data indication, or
   // a response to a previous request.