clang/win: Build chromium code without -Wno-incompatible-pointer-types.

third_party/iaccessible2/iaccessible2.gyp

 # Copyright (c) 2012 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.
 
 {
   'variables': {
     'midl_out_dir': '<(SHARED_INTERMEDIATE_DIR)/third_party/iaccessible2',
   },
   'targets': [
     {
@@ skipping 25 matching lines @@
       'sources': [
         'IAccessible2Proxy.def',
         '<(midl_out_dir)/dlldata.c',
         '<(midl_out_dir)/ia2_api_all_p.c',
       ],
       'link_settings': {
         'libraries': [
           '-lrpcrt4.lib',
         ],
       },
+      'variables': {
+        'clang_warning_flags': [
+          '-Wno-incompatible-pointer-types',
+        ]
+      },
     },
   ],
 }