Add a Preference to allow WebRTC only bind to "any address" (all 0s)

content/renderer/p2p/port_allocator.cc

Index: content/renderer/p2p/port_allocator.cc
diff --git a/content/renderer/p2p/port_allocator.cc b/content/renderer/p2p/port_allocator.cc
index 7beb3ecc444f6564fd39cf6f859fb9b5b2ea9f85..19c72d433d4cbfcb12dde0da722e389adb14f659 100644
--- a/content/renderer/p2p/port_allocator.cc
+++ b/content/renderer/p2p/port_allocator.cc
@@ -31,6 +31,8 @@ P2PPortAllocator::P2PPortAllocator(
   uint32 flags = 0;
   if (config_.disable_tcp_transport)
     flags |= cricket::PORTALLOCATOR_DISABLE_TCP;
+  if (config_.disable_multiple_routes)
+    flags |= cricket::PORTALLOCATOR_DISABLE_ADAPTER_ENUMERATION;
   set_flags(flags);
   set_allow_tcp_listen(false);
 }