Relanding Generate localhost candidate when no STUN/TURN and portallocator has the right flag spefi…

webrtc/p2p/base/portallocator.h

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 25 matching lines @@
   PORTALLOCATOR_ENABLE_IPV6 = 0x40,
   // TODO(pthatcher): Remove this once it's no longer used in:
   // remoting/client/plugin/pepper_port_allocator.cc
   // remoting/protocol/chromium_port_allocator.cc
   // remoting/test/fake_port_allocator.cc
   // It's a no-op and is no longer needed.
   PORTALLOCATOR_ENABLE_SHARED_UFRAG = 0x80,
   PORTALLOCATOR_ENABLE_SHARED_SOCKET = 0x100,
   PORTALLOCATOR_ENABLE_STUN_RETRANSMIT_ATTRIBUTE = 0x200,
   PORTALLOCATOR_DISABLE_ADAPTER_ENUMERATION = 0x400,
+  // When specified, a loopback candidate will be generated if
+  // PORTALLOCATOR_DISABLE_ADAPTER_ENUMERATION is specified.
+  PORTALLOCATOR_ENABLE_LOCALHOST_CANDIDATE = 0x800,
 };
 
 const uint32 kDefaultPortAllocatorFlags = 0;
 
 const uint32 kDefaultStepDelay = 1000;  // 1 sec step delay.
 // As per RFC 5245 Appendix B.1, STUN transactions need to be paced at certain
 // internal. Less than 20ms is not acceptable. We choose 50ms as our default.
 const uint32 kMinimumStepDelay = 50;
 
 // CF = CANDIDATE FILTER
@@ skipping 129 matching lines @@
   int max_port_;
   uint32 step_delay_;
   bool allow_tcp_listen_;
   uint32 candidate_filter_;
   std::string origin_;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_PORTALLOCATOR_H_