Turn off ipv6 when there is no support at startup....

net/base/host_resolver_proc.cc

Index: net/base/host_resolver_proc.cc
===================================================================
--- net/base/host_resolver_proc.cc	(revision 38072)
+++ net/base/host_resolver_proc.cc	(working copy)
@@ -227,4 +227,27 @@
   return OK;
 }
 
+// TODO(jar): The following is a simple estimate of ipv6 support.  We may need
+// to do a test resolution, and a test connection, to REALLY verify support.
+// static
+bool HostResolverProc::IPv6Supported() {
+#if defined(OS_POSIX)
+  int test_socket;
+#else
+  SOCKET test_socket;
+#endif
+
+  test_socket = socket(AF_INET6, SOCK_STREAM, 0);
+  if (test_socket == -1)
+    return false;
+
+#if defined(OS_POSIX)
+  close(test_socket);
+#else
+  closesocket(test_socket);
+#endif
+
+  return true;
+}
+
 }  // namespace net