clang: Turn on -Wabsolute-value.

third_party/libexif/libexif.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': {
     'conditions': [
       ['OS == "linux" and chromeos==0', {
         'use_system_libexif%': 1,
       }, {  # OS != "linux" and chromeos==0
@@ skipping 38 matching lines @@
           ],
           'direct_dependent_settings': {
             'include_dirs': [
               'sources',
             ],
           },
           'conditions': [
             ['clang==1', {
               'cflags': [
                 '-Wno-enum-conversion', 
-                '-Wno-switch'
+                '-Wno-switch',
+                # libexif uses fabs(int) to cast to float.
+                '-Wno-absolute-value',
               ],
               'xcode_settings': {
                 'WARNING_CFLAGS': [
                   '-Wno-enum-conversion', 
                   '-Wno-switch',
                   '-Wno-format',
+                  # libexif uses fabs(int) to cast to float.
+                  '-Wno-absolute-value',
                 ],
               },
             }],
             ['os_posix==1 and OS!="mac"', {
               'cflags!': ['-fvisibility=hidden'],
             }],
             ['OS=="mac"', {
               'conditions': [
                ['mac_breakpad==1', {
                   'variables': {
@@ skipping 45 matching lines @@
             ],
             'defines': [
               'USE_SYSTEM_LIBEXIF',
             ],
           },
         }
       ],
     }],
   ]
 }