Update existing uses of /wd4267 to use the GN config

win8/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.
 
 source_set("metro_viewer_constants") {
   sources = [
     "viewer/metro_viewer_constants.cc",
     "viewer/metro_viewer_constants.h",
   ]
 }
@@ skipping 11 matching lines @@
     "viewer/metro_viewer_process_host.h",
   ]
   defines = [ "METRO_VIEWER_IMPLEMENTATION" ]
 }
 
 source_set("test_support_win8") {
   deps = [
     "//base",
     ":test_registrar_constants",
   ]
+
+  # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+
   sources = [
     "test/metro_registration_helper.cc",
     "test/metro_registration_helper.h",
     "test/open_with_dialog_async.cc",
     "test/open_with_dialog_async.h",
     "test/open_with_dialog_controller.cc",
     "test/open_with_dialog_controller.h",
     "test/ui_automation_client.cc",
     "test/ui_automation_client.h",
   ]
-
-  # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
-  cflags = [ "/wd4267" ]
 }
 
 source_set("test_registrar_constants") {
   sources = [
     "test/test_registrar_constants.cc",
     "test/test_registrar_constants.h",
   ]
 }
 
 executable("test_registrar") {
   deps = [
     "//base",
 
     # Chrome is the default viewer process currently used by the tests.
     # TODO(robertshield): Investigate building a standalone metro viewer
     # process.
     "//chrome",
     ":test_registrar_constants",
   ]
   sources = [
     "test/test_registrar.cc",
     "test/test_registrar.rc",
     "test/test_registrar.rgs",
     "test/test_registrar_resource.h",
   ]
   configs += [ "//build/config/win:windowed" ]
 }