Refactor window frame painting into a window background class

ui/views/views.gyp

 # Copyright (c) 2011 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,
   },
 
   'target_defaults': {
     'conditions': [
@@ skipping 360 matching lines @@
         'widget/window_manager.cc',
         'widget/window_manager.h',
         'window/client_view.cc',
         'window/client_view.h',
         'window/custom_frame_view.cc',
         'window/custom_frame_view.h',
         'window/dialog_client_view.cc',
         'window/dialog_client_view.h',
         'window/dialog_delegate.cc',
         'window/dialog_delegate.h',
+        'window/frame_background.cc',
+        'window/frame_background.h',
         'window/native_frame_view.cc',
         'window/native_frame_view.h',
         'window/non_client_view.cc',
         'window/non_client_view.h',
         'window/window_resources.h',
         'window/window_shape.cc',
         'window/window_shape.h',
       ],
       'include_dirs': [
         '../../third_party/wtl/include',
@@ skipping 347 matching lines @@
           'msvs_settings': {
             'VCManifestTool': {
               'AdditionalManifestFiles': 'examples\\views_examples.exe.manifest',
             },
           },
         }],
       ],
     },  # target_name: views_examples_lib
   ],
 }