Chromecast: adds disable_display define for headless builds.

chromecast/chromecast.gyp

 # Copyright 2014 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': {
     'android_support_v13_target%':
         '../third_party/android_tools/android_tools.gyp:android_support_v13_javalib',
     'chromium_code': 1,
     'chromecast_branding%': 'Chromium',
+    'disable_display%': 0,
   },
   'includes': [
     'chromecast_tests.gypi',
   ],
   'target_defaults': {
     'include_dirs': [
       '..',  # Root of Chromium checkout
     ],
+    'conditions': [
+      ['disable_display==1', {
+        'defines': ['DISABLE_DISPLAY'],
+      }],
+    ],
   },
   'targets': [
     # TODO(gunsch): Remove these fake targets once they're either added or no
     # longer referenced from internal code.
     {'target_name': 'cast_media_audio', 'type': 'none'},
     {'target_name': 'cast_port_impl', 'type': 'none'},
 
     {
       'target_name': 'cast_base',
       'type': '<(component)',
@@ skipping 460 matching lines @@
             'cast_shell_core',
           ],
           'sources': [
             'app/cast_main.cc',
           ],
         },
       ],  # end of targets
     }],
   ],  # end of conditions
 }