Add missing dependency of audio_unittests on xdisplaycheck.

media/media.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,
     # Override to dynamically link the cras (ChromeOS audio) library.
     'use_cras%': 0,
     # Option e.g. for Linux distributions to link pulseaudio directly
@@ skipping 1946 matching lines @@
           'type': 'none',
           'dependencies': [
             'audio_unittests',
           ],
           'includes': [
             '../build/isolate.gypi',
           ],
           'sources': [
             'audio_unittests.isolate',
           ],
+          'conditions': [
+            ['use_x11==1', {
+              'dependencies': [
+                '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
+              ],
+            }],
+          ],
         },
       ],
     }],
   ],
 }