Revert broken Linux hidpi changes.

chrome/browser/ui/libgtk2ui/libgtk2ui.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': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 25 matching lines @@
         '../../../../ui/shell_dialogs/shell_dialogs.gyp:shell_dialogs',
         '../../../../ui/strings/ui_strings.gyp:ui_strings',
         '../../../../ui/views/views.gyp:views',
         '../../../chrome_resources.gyp:chrome_extra_resources',
         '../../../chrome_resources.gyp:chrome_resources',
         '../../../chrome_resources.gyp:chrome_strings',
         '../../../chrome_resources.gyp:theme_resources',
       ],
       'defines': [
         'LIBGTK2UI_IMPLEMENTATION',
-        # g_settings_list_schemas is deprecated, but this function is not
-        # available on earlier version that we still need to support.
-        # See build/linux/system.gyp:gio for details.
-        'GLIB_DISABLE_DEPRECATION_WARNINGS'
       ],
       # Several of our source files are named _gtk2.cc. This isn't to
       # differentiate them from their source files (ninja and make are sane
       # build systems, unlike MSVS). It is instead to get around the rest of
       # the normal, global gtk exclusion rules, as we are otherwise using gtk
       # in a non-gtk build.
       'sources': [
         # Note: sources list duplicated in GN build.
         'app_indicator_icon.cc',
         'app_indicator_icon.h',
@@ skipping 57 matching lines @@
             '-Wno-unused-function',
 
             # G_STATIC_ASSERT uses a typedef as a static_assert.
             '-Wno-unused-local-typedef',
           ],
         }],
       ],
     },
   ],
 }