clang/win: Take another stab at building with -Wunused-private-field.

third_party/libphonenumber/libphonenumber.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.
 
 {
   'target_defaults': {
     'include_dirs': [
       'src',
       'src/test',
       # The libphonenumber source (and test code) expects the
@@ skipping 48 matching lines @@
       'src/phonenumbers/unicodestring.cc',
       'src/phonenumbers/utf/rune.c',
       'src/phonenumbers/utf/unicodetext.cc',
       'src/phonenumbers/utf/unilib.cc',
       'src/resources/phonemetadata.proto',
       'src/resources/phonenumber.proto',
     ],
     'variables': {
       'proto_in_dir': 'src/resources',
       'proto_out_dir': 'third_party/libphonenumber/phonenumbers',
+      'clang_warning_flags': [
+        # https://github.com/googlei18n/libphonenumber/pull/741
+        '-Wno-unused-private-field',
+      ],
     },
     'includes': [ '../../build/protoc.gypi' ],
     'direct_dependent_settings': {
       'include_dirs': [
         '<(SHARED_INTERMEDIATE_DIR)/protoc_out/third_party/libphonenumber',
         'src',
       ],
       'defines': [
         'I18N_PHONENUMBERS_USE_ICU_REGEXP=1',
       ],
@@ skipping 63 matching lines @@
       }],
       # libphonenumber needs to fix their ODR violations. http://crbug.com/456021
       ['OS=="linux"', {
         'ldflags!': [
           '-Wl,--detect-odr-violations',
         ],
       }],
     ],
   }]
 }