url: add missing url_util_internal.h to the corresponding BUILD.gn file

url/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/buildflag_header.gni")
 import("//testing/test.gni")
 import("features.gni")
 
 if (is_android) {
   import("//build/config/android/rules.gni")
@@ skipping 33 matching lines @@
     "url_canon_stdstring.h",
     "url_canon_stdurl.cc",
     "url_constants.cc",
     "url_constants.h",
     "url_export.h",
     "url_file.h",
     "url_parse_file.cc",
     "url_parse_internal.h",
     "url_util.cc",
     "url_util.h",
+    "url_util_internal.h",
   ]
 
   defines = [ "URL_IMPLEMENTATION" ]
 
   configs += [
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     "//build/config/compiler:no_size_t_to_int_warning",
   ]
 
   deps = [
@@ skipping 100 matching lines @@
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 
   if (!is_ios) {
     deps += [
       "//mojo/edk/system",
       "//mojo/edk/test:test_support",
       "//url/mojo:test_url_mojom_gurl",
     ]
   }
 }