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

webrtc/p2p/base/port.h

Index: webrtc/p2p/base/port.h
diff --git a/webrtc/p2p/base/port.h b/webrtc/p2p/base/port.h
index 65932b9c9f0f400636fca9f558a2bc04b68456de..5d95b80a5be8cc0dd7cec3e7e9f02215ec5794ad 100644
--- a/webrtc/p2p/base/port.h
+++ b/webrtc/p2p/base/port.h
@@ -523,6 +523,10 @@
   // Makes the connection go away, in a failed state.
   void FailAndDestroy();
 
+  // Prunes the connection and sets its state to STATE_FAILED,
+  // It will not be used or send pings although it can still receive packets.
+  void FailAndPrune();
+
   // Checks that the state of this connection is up-to-date.  The argument is
   // the current time, which is compared against various timeouts.
   void UpdateState(int64_t now);