Revert 107563 - Fix up compositor mocking.

content/content_plugin.gypi

 # 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.
 
 {
   'dependencies': [
     '../skia/skia.gyp:skia',
     '../third_party/npapi/npapi.gyp:npapi',
     '../webkit/support/webkit_support.gyp:glue',
   ],
@@ skipping 36 matching lines @@
     ['toolkit_uses_gtk == 1', {
       'dependencies': [
         '../build/linux/system.gyp:gtk',
       ],
       'link_settings': {
         'libraries': [
           '-lXext',
         ],
       },
     }],
-    ['use_aura==1 and OS!="win"', {
-      'link_settings': {
-        'libraries': [
-          '-lXext',
-        ],
-      },
-    }],
   ],
 }