Reland of Do not delete a connection in the turn port with permission error or refresh error.

webrtc/p2p/base/port.cc

Index: webrtc/p2p/base/port.cc
diff --git a/webrtc/p2p/base/port.cc b/webrtc/p2p/base/port.cc
index 6e26371daedd93620cfee32f7d58cc6fd68dbb47..d4dfd91ecaa56ebc176ba215b9d2b2ef7664f691 100644
--- a/webrtc/p2p/base/port.cc
+++ b/webrtc/p2p/base/port.cc
@@ -1088,6 +1088,11 @@
 void Connection::FailAndDestroy() {
   set_state(Connection::STATE_FAILED);
   Destroy();
+}
+
+void Connection::FailAndPrune() {
+  set_state(Connection::STATE_FAILED);
+  Prune();
 }
 
 void Connection::PrintPingsSinceLastResponse(std::string* s, size_t max) {