Refactor the wallpaper encoding to another file/class.

chrome/chrome_browser.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'browser',
       'type': 'static_library',
@@ skipping 4069 matching lines @@
         'browser/ui/webui/options2/chromeos/language_options_util.cc',
         'browser/ui/webui/options2/chromeos/language_options_util.h',
         'browser/ui/webui/options2/chromeos/language_pinyin_handler.cc',
         'browser/ui/webui/options2/chromeos/language_pinyin_handler.h',
         'browser/ui/webui/options2/chromeos/pointer_handler.cc',
         'browser/ui/webui/options2/chromeos/pointer_handler.h',
         'browser/ui/webui/options2/chromeos/proxy_handler.cc',
         'browser/ui/webui/options2/chromeos/proxy_handler.h',
         'browser/ui/webui/options2/chromeos/set_wallpaper_options_handler.cc',
         'browser/ui/webui/options2/chromeos/set_wallpaper_options_handler.h',
+        'browser/ui/webui/options2/chromeos/simple_png_encoder.cc',
+        'browser/ui/webui/options2/chromeos/simple_png_encoder.h',
         'browser/ui/webui/options2/chromeos/stats_options_handler.cc',
         'browser/ui/webui/options2/chromeos/stats_options_handler.h',
         'browser/ui/webui/options2/chromeos/timezone_options_util.cc',
         'browser/ui/webui/options2/chromeos/timezone_options_util.h',
         'browser/ui/webui/options2/chromeos/user_image_source.cc',
         'browser/ui/webui/options2/chromeos/user_image_source.h',
         'browser/ui/webui/options2/chromeos/wallpaper_source.cc',
         'browser/ui/webui/options2/chromeos/wallpaper_source.h',
         'browser/ui/webui/options2/chromeos/wallpaper_thumbnail_source.cc',
         'browser/ui/webui/options2/chromeos/wallpaper_thumbnail_source.h',
@@ skipping 1364 matching lines @@
           'variables': {
             'jni_gen_dir': 'chrome',
           },
           'includes': [ '../build/jni_generator.gypi' ],
         },
       ],
      },
     ],
   ],
 }