Remove ports that are not used by any channel after timeout

webrtc/p2p/base/fakeportallocator.h

Index: webrtc/p2p/base/fakeportallocator.h
diff --git a/webrtc/p2p/base/fakeportallocator.h b/webrtc/p2p/base/fakeportallocator.h
index 001308543ea47e7692949a4e77d1c13343618e2e..a1dbbf872b152748588ecd6b8727c5fc7c341305 100644
--- a/webrtc/p2p/base/fakeportallocator.h
+++ b/webrtc/p2p/base/fakeportallocator.h
@@ -149,6 +149,7 @@ class FakePortAllocatorSession : public PortAllocatorSession {
   std::vector<Candidate> ReadyCandidates() const override {
     return candidates_;
   }
+  void PruneAllPorts() override { port_->Prune(); }
   bool CandidatesAllocationDone() const override { return allocation_done_; }
 
   int port_config_count() { return port_config_count_; }
@@ -181,6 +182,7 @@ class FakePortAllocatorSession : public PortAllocatorSession {
     port->PrepareAddress();
     ready_ports_.push_back(port);
     SignalPortReady(this, port);
+    port->KeepAliveUntilPruned();
   }
   void OnPortComplete(cricket::Port* port) {
     const std::vector<Candidate>& candidates = port->Candidates();