Put back allow_circular_includes_from in GN build.

content/public/utility/BUILD.gn

 # Copyright 2014 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.
 
 # See //content/BUILD.gn for how this works.
 group("utility") {
   if (is_component_build) {
     deps = [ "//content" ]
   } else {
     deps = [ ":utility_sources" ]
@@ skipping 17 matching lines @@
     "//base",
     "//content:export",
     "//content/public/common:common_sources",
     "//content/utility",
     "//ipc",
   ]
 
   allow_circular_includes_from = [
     # This target is a pair with content/browser. They always go together and
     # include headers from each other.
-    # TODO(brettw) enable this when this permits non-dependent targets.
-    #"//content/utility",
+    "//content/utility",
   ]
 }