aura: A few changes to have aura_demo compile and run on linux.

ui/ui.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,
     'toolkit_views2': 0,  # ui/views/ is an experimental framework on Windows.
   },
   'target_defaults': {
@@ skipping 276 matching lines @@
         'gfx/skia_util.cc',
         'gfx/skia_util.h',
         'gfx/skia_utils_gtk.cc',
         'gfx/skia_utils_gtk.h',
         'gfx/transform.h',
         'gfx/transform.cc',
       ],
       'conditions': [
         ['use_aura==1', {
           'sources/': [
+            ['exclude', 'gfx/gtk_'],
+            ['exclude', 'gfx/screen_gtk.cc'],
             ['exclude', 'gfx/screen_win.cc'],
             ['exclude', 'base/win/mouse_wheel_util.cc'],
-            ['exclude', 'base/win/mouse_wheel_util.h'],            
+            ['exclude', 'base/win/mouse_wheel_util.h'],
           ],
         }],
         ['toolkit_uses_gtk == 1', {
           'dependencies': [
             # font_gtk.cc uses fontconfig.
             # TODO(evanm): I think this is wrong; it should just use GTK.
             '../build/linux/system.gyp:fontconfig',
             '../build/linux/system.gyp:gtk',
             '../build/linux/system.gyp:x11',
             '../build/linux/system.gyp:xext',
           ],
           'sources': [
             'gfx/gtk_native_view_id_manager.cc',
             'gfx/gtk_native_view_id_manager.h',
             'gfx/gtk_preserve_window.cc',
             'gfx/gtk_preserve_window.h',
             'gfx/gtk_util.cc',
             'gfx/gtk_util.h',
+            'gfx/linux_util.cc',
+            'gfx/linux_util.h',
             'gfx/native_theme_linux.cc',
             'gfx/native_theme_linux.h',
           ],
           'link_settings': {
             'libraries': [
               '-lXrender',  # For XRender* function calls in x11_util.cc.
             ],
           },
           'conditions': [
             ['toolkit_views==0', {
@@ skipping 25 matching lines @@
             ['include', 'base/dragdrop/os_exchange_data_provider_gtk.h'],
             ['include', 'base/keycodes/keyboard_code_conversion_x.cc'],
             ['include', 'base/keycodes/keyboard_code_conversion_x.h'],
             ['include', 'base/view_prop.cc'],
             ['include', 'base/view_prop.h'],
             ['include', 'gfx/gtk_util.cc'],
             ['include', 'gfx/gtk_util.h'],
             ['include', 'gfx/path_gtk.cc'],
             ['include', 'gfx/platform_font_gtk.cc'],
             ['include', 'gfx/platform_font_gtk.h'],
+            ['include', 'gfx/linux_util.cc'],
+            ['include', 'gfx/linux_util.h'],
           ],
         }],
         ['OS=="win"', {
           'sources': [
             'gfx/canvas_direct2d.cc',
             'gfx/canvas_direct2d.h',
             'gfx/gdi_util.cc',
             'gfx/gdi_util.h',
             'gfx/icon_util.cc',
             'gfx/icon_util.h',
@@ skipping 167 matching lines @@
           'configurations': {
             'Common_Base': {
               'msvs_target_platform': 'x64',
             },
           },
         },
       ],
     }],
   ],
 }