Enable hidpi on Linux, refactor a bit on Windows to share

ui/base/ui_base.gyp

 # Copyright 2014 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 326 matching lines @@
         'view_prop.cc',
         'view_prop.h',
         'webui/jstemplate_builder.cc',
         'webui/jstemplate_builder.h',
         'webui/web_ui_util.cc',
         'webui/web_ui_util.h',
         'win/accessibility_ids_win.h',
         'win/accessibility_misc_utils.cc',
         'win/accessibility_misc_utils.h',
         'win/atl_module.h',
-        'win/dpi_setup.cc',
-        'win/dpi_setup.h',
         'win/foreground_helper.cc',
         'win/foreground_helper.h',
         'win/hidden_window.cc',
         'win/hidden_window.h',
         'win/hwnd_subclass.cc',
         'win/hwnd_subclass.h',
         'win/internal_constants.cc',
         'win/internal_constants.h',
         'win/lock_state.cc',
         'win/lock_state.h',
@@ skipping 398 matching lines @@
            ],
            'variables': {
              'jni_gen_package': 'ui',
            },
            'includes': [ '../../build/jni_generator.gypi' ],
          },
        ],
     }],
   ],
 }