Update woff2 to 2bc6acf

third_party/woff2/woff2.gyp

 # Copyright 2015 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.
 
 {
   'targets': [
     {
       'target_name': 'woff2_dec',
       'type': 'static_library',
       'include_dirs': [
@@ skipping 15 matching lines @@
         'src/woff2_common.h',
         'src/woff2_dec.cc',
         'src/woff2_dec.h',
         'src/woff2_out.cc',
         'src/woff2_out.h',
       ],
       # TODO(ksakamoto): http://crbug.com/167187
       'msvs_disabled_warnings': [
         4267,
       ],
-      'variables': {
-        'clang_warning_flags': [
-          '-Wno-unused-function',
-        ],
-      },
     },
   ],
 }