pull gflags.gyp changes from webrtc

third_party/gflags/gflags.gyp

 #
 # Copyright 2014 The LibYuv Project Authors. All rights reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS. All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 # This is a copy of WebRTC's gflags.gyp.
@@ skipping 58 matching lines @@
               'AdditionalOptions!': [
                 '-Wheader-hygiene',  # Suppress warning about using namespace.
               ],
               'AdditionalOptions': [
                 '-Wno-unused-local-typedef',  # Suppress unused private typedef.
               ],
             },
           },
         }],
         ['clang==1', {
+          'cflags': ['-Wno-unused-local-typedef',],
           'cflags!': ['-Wheader-hygiene',],
           'xcode_settings': {
+            'WARNING_CFLAGS': ['-Wno-unused-local-typedef',],
             'WARNING_CFLAGS!': ['-Wheader-hygiene',],
           },
         }],
       ],
     },
   ],
 }
+