Rolling libwebp broke our iOS builds. Silence warnings instead.

gyp/libwebp.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': {
     'skia_warnings_as_errors': 0,
     'conditions':[
       ['skia_android_framework == 1', {
         'use_system_libwebp': 1,
@@ skipping 18 matching lines @@
             '../third_party/externals/libwebp/src/dec/idec.c',
             '../third_party/externals/libwebp/src/dec/io.c',
             '../third_party/externals/libwebp/src/dec/layer.c',
             '../third_party/externals/libwebp/src/dec/quant.c',
             '../third_party/externals/libwebp/src/dec/tree.c',
             '../third_party/externals/libwebp/src/dec/vp8.c',
             '../third_party/externals/libwebp/src/dec/vp8l.c',
             '../third_party/externals/libwebp/src/dec/webp.c',
           ],
           'cflags': [ '-w' ],
+          'xcode_settings': { 'WARNING_CFLAGS': [ '-w' ] },
         },
         {
           'target_name': 'libwebp_demux',
           'type': 'static_library',
           'include_dirs': [
               '../third_party/externals/libwebp',
           ],
           'sources': [
             '../third_party/externals/libwebp/src/demux/demux.c',
           ],
           'cflags': [ '-w' ],
+          'xcode_settings': { 'WARNING_CFLAGS': [ '-w' ] },
         },
         {
           'target_name': 'libwebp_dsp',
           'type': 'static_library',
           'include_dirs': [
               '../third_party/externals/libwebp',
           ],
           'sources': [
             '../third_party/externals/libwebp/src/dsp/cpu.c',
             '../third_party/externals/libwebp/src/dsp/dec.c',
             '../third_party/externals/libwebp/src/dsp/dec_sse2.c',
             '../third_party/externals/libwebp/src/dsp/enc.c',
             '../third_party/externals/libwebp/src/dsp/enc_sse2.c',
             '../third_party/externals/libwebp/src/dsp/lossless.c',
             '../third_party/externals/libwebp/src/dsp/upsampling.c',
             '../third_party/externals/libwebp/src/dsp/upsampling_sse2.c',
             '../third_party/externals/libwebp/src/dsp/yuv.c',
           ],
           'cflags': [ '-w' ],
+          'xcode_settings': { 'WARNING_CFLAGS': [ '-w' ] },
           'conditions': [
             ['skia_os == "android"', {
               'dependencies' : [
                 'android_deps.gyp:cpu_features',
               ],
             }],
           ],
         },
         {
           'target_name': 'libwebp_dsp_neon',
@@ skipping 37 matching lines @@
             '../third_party/externals/libwebp/src/enc/layer.c',
             '../third_party/externals/libwebp/src/enc/picture.c',
             '../third_party/externals/libwebp/src/enc/quant.c',
             '../third_party/externals/libwebp/src/enc/syntax.c',
             '../third_party/externals/libwebp/src/enc/token.c',
             '../third_party/externals/libwebp/src/enc/tree.c',
             '../third_party/externals/libwebp/src/enc/vp8l.c',
             '../third_party/externals/libwebp/src/enc/webpenc.c',
           ],
           'cflags': [ '-w' ],
+          'xcode_settings': { 'WARNING_CFLAGS': [ '-w' ] },
         },
         {
           'target_name': 'libwebp_utils',
           'type': 'static_library',
           'include_dirs': [
               '../third_party/externals/libwebp',
           ],
           'sources': [
             '../third_party/externals/libwebp/src/utils/bit_reader.c',
             '../third_party/externals/libwebp/src/utils/bit_writer.c',
             '../third_party/externals/libwebp/src/utils/color_cache.c',
             '../third_party/externals/libwebp/src/utils/filters.c',
             '../third_party/externals/libwebp/src/utils/huffman.c',
             '../third_party/externals/libwebp/src/utils/huffman_encode.c',
             '../third_party/externals/libwebp/src/utils/quant_levels.c',
             '../third_party/externals/libwebp/src/utils/quant_levels_dec.c',
             '../third_party/externals/libwebp/src/utils/rescaler.c',
             '../third_party/externals/libwebp/src/utils/thread.c',
             '../third_party/externals/libwebp/src/utils/utils.c',
           ],
           'cflags': [ '-w' ],
+          'xcode_settings': { 'WARNING_CFLAGS': [ '-w' ] },
         },
         {
           'target_name': 'libwebp',
           'type': 'none',
           'dependencies' : [
             'libwebp_dec',
             'libwebp_demux',
             'libwebp_dsp',
             'libwebp_dsp_neon',
             'libwebp_enc',
@@ skipping 41 matching lines @@
                   ],
                 },
               },
             ],
           ],
         }
       ],
     }],
   ],
 }