ui: accessibility: remove -Wunused-function for Atk

ui/accessibility/accessibility.gyp

 # Copyright 2013 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': {
     'chromium_code': 1,
   },
 
   'targets': [
@@ skipping 55 matching lines @@
         ['OS=="linux" and chromeos==0 and use_x11==1', {
           'dependencies': [
             '../../build/linux/system.gyp:atk',
             '../../build/linux/system.gyp:gconf',
             '../../build/linux/system.gyp:glib',
           ],
           'variables': {
             'clang_warning_flags': [
               # glib uses the pre-c++11 typedef-as-static_assert hack.
               '-Wno-unused-local-typedefs',
+              # G_DEFINE_TYPE automatically generates a
+              # *get_instance_private inline function after glib 2.37.
+              # That's unused. Prevent to complain about it.
+              '-Wno-unused-function',
             ],
           },
         }],
         ['OS!="linux" or chromeos==1 or use_x11==0', {
           'sources!': [
             'platform/ax_platform_node_auralinux.cc',
             'platform/ax_platform_node_auralinux.h',
             'platform/atk_util_auralinux.cc',
             'platform/atk_util_auralinux.h',
           ],
@@ skipping 120 matching lines @@
           'type': 'none',
           'variables': {
             'source_file': 'ax_enums.idl',
           },
           'includes': [ '../../build/android/java_cpp_enum.gypi' ],
         },
       ],
     }],
   ],
 }