x11: Include X11 dependencies only when building with X11.

base/base.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,
   },
   'includes': [
     '../build/win_precompile.gypi',
@@ skipping 44 matching lines @@
                 '../build/linux/system.gyp:gtk',
               ],
               'export_dependent_settings': [
                 '../build/linux/system.gyp:gtk',
               ],
             }],
           ],
           'dependencies': [
             'symbolize',
             '../build/linux/system.gyp:glib',
-            '../build/linux/system.gyp:x11',
             'xdg_mime',
           ],
           'defines': [
             'USE_SYMBOLIZE',
           ],
           'cflags': [
             '-Wno-write-strings',
           ],
           'export_dependent_settings': [
             '../build/linux/system.gyp:glib',
-            '../build/linux/system.gyp:x11',
           ],
         }, {  # use_glib!=1
             'sources/': [
               ['exclude', '/xdg_user_dirs/'],
               ['exclude', '_nss\\.cc$'],
             ],
         }],
+        ['use_x11==1', {
+          'dependencies': [
+            '../build/linux/system.gyp:x11',
+          ],
+          'export_dependent_settings': [
+            '../build/linux/system.gyp:x11',
+          ],
+        }],
         ['OS == "android" and _toolset == "host"', {
           # Base for host support is the minimum required to run the
           # ssl false start blacklist tool. It requires further changes
           # to generically support host builds (and tests).
           # Note: when building for host, gyp has OS == "android",
           # hence the *_android.cc files are included but the actual code
           # doesn't have OS_ANDROID / ANDROID defined.
           'conditions': [
             # Host build on linux depends on system.gyp::gtk as
             # default linux build has TOOLKIT_GTK defined.
@@ skipping 1115 matching lines @@
             'base_unittests.isolate',
           ],
           'sources': [
             'base_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }