release the turn allocation by sending a refresh request with lifetime 0

BUG=406578

Patch originally from philipp.hancke@googlemail.com

R=juberti@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/41449004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@8087 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/p2p/base/stunrequest.cc b/webrtc/p2p/base/stunrequest.cc
index a6f4c15..32b4694 100644
--- a/webrtc/p2p/base/stunrequest.cc
+++ b/webrtc/p2p/base/stunrequest.cc
@@ -44,7 +44,11 @@
   request->set_origin(origin_);
   request->Construct();
   requests_[request->id()] = request;
-  thread_->PostDelayed(delay, request, MSG_STUN_SEND, NULL);
+  if (delay > 0) {
+    thread_->PostDelayed(delay, request, MSG_STUN_SEND, NULL);
+  } else {
+    thread_->Send(request, MSG_STUN_SEND, NULL);
+  }
 }
 
 void StunRequestManager::Remove(StunRequest* request) {