Make it possible to keep the port allocator session running

webrtc/p2p/base/p2ptransportchannel.cc

Index: webrtc/p2p/base/p2ptransportchannel.cc
diff --git a/webrtc/p2p/base/p2ptransportchannel.cc b/webrtc/p2p/base/p2ptransportchannel.cc
index 2a851f5c7259cf32c22d66b149b8e059249ed939..2cd1beb300514544bab8573be614f6369a5c8d6d 100644
--- a/webrtc/p2p/base/p2ptransportchannel.cc
+++ b/webrtc/p2p/base/p2ptransportchannel.cc
@@ -1070,7 +1070,7 @@ void P2PTransportChannel::HandleWritable() {
   if (!writable()) {
     for (uint32 i = 0; i < allocator_sessions_.size(); ++i) {
       if (allocator_sessions_[i]->IsGettingPorts()) {
-        allocator_sessions_[i]->StopGettingPorts();
+        allocator_sessions_[i]->StopGettingPorts(false);
       }
     }
   }