Make the gyp files more cross-platform across the Unices

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': {
     'sources/': [
       ['exclude', '/(cocoa|gtk|win)/'],
       ['exclude', '_(cocoa|gtk|linux|mac|posix|win|x)\\.(cc|mm?)$'],
       ['exclude', '/(gtk|win|x11)_[^/]*\\.cc$'],
     ],
     'conditions': [
-      ['OS=="linux" or OS=="freebsd" or OS=="openbsd"', {'sources/': [
-        ['include', '/gtk/'],
-        ['include', '_(gtk|linux|posix|skia|x)\\.cc$'],
-        ['include', '/(gtk|x11)_[^/]*\\.cc$'],
-      ]}],
+      ['toolkit_uses_gtk == 1', {
+        'sources/': [
+          ['include', '/gtk/'],
+          ['include', '_(gtk|linux|posix|skia|x)\\.cc$'],
+          ['include', '/(gtk|x11)_[^/]*\\.cc$'],
+        ],
+      }],
       ['OS=="mac"', {'sources/': [
         ['include', '/cocoa/'],
         ['include', '_(cocoa|mac|posix)\\.(cc|mm?)$'],
       ]}, { # else: OS != "mac"
         'sources/': [
           ['exclude', '\\.mm?$'],
         ],
       }],
       ['OS=="win"',
         {'sources/': [
@@ skipping 31 matching lines @@
       ],
     }],
   ],
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: