Adding PortAllocator option to support cases where sockets can't be bound.

webrtc/p2p/base/portallocator.h

Index: webrtc/p2p/base/portallocator.h
diff --git a/webrtc/p2p/base/portallocator.h b/webrtc/p2p/base/portallocator.h
index a77b037e7294133973f83bc41f49ba2dabb836bc..a74acce96d49c1288aaca9637b85f4c428fb6a5c 100644
--- a/webrtc/p2p/base/portallocator.h
+++ b/webrtc/p2p/base/portallocator.h
@@ -77,6 +77,14 @@ enum {
 
   // When specified, do not collect IPv6 ICE candidates on Wi-Fi.
   PORTALLOCATOR_ENABLE_IPV6_ON_WIFI = 0x4000,
+
+  // When this flag is set, ports will be created not bound to any specific
+  // network interface, in addition to normal ports. Without this flag, these
+  // ports would only be used when network enumeration fails or is disabled.
+  // But under certain conditions, these ports may succeed where others fail,
+  // so they may allow the application to work in a wider variety of
+  // environments, at the expense of having to allocate additional candidates.
+  PORTALLOCATOR_ENABLE_ANY_ADDRESS_PORTS = 0x8000,
 };
 
 // Defines various reasons that have caused ICE regathering.