Hide X11 dependencies when use_x11=0.

chrome/chrome_browser_extensions.gypi

 # Copyright (c) 2013 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.
 
 {
   'targets': [
     {
       'target_name': 'browser_extensions',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 1018 matching lines @@
             '../device/bluetooth/bluetooth.gyp:device_bluetooth',
             '../third_party/libusb/libusb.gyp:libusb'
           ],
         }],
         ['use_aura==1', {
           'dependencies': [
             '../ui/keyboard/keyboard.gyp:keyboard',
             '../ui/keyboard/keyboard.gyp:keyboard_resources',
           ],
         }],
-        ['OS=="linux" and use_aura==1', {
-          'dependencies': [
-            '../build/linux/system.gyp:dbus',
-            '../build/linux/system.gyp:fontconfig',
-            '../build/linux/system.gyp:x11',
-            '../dbus/dbus.gyp:dbus',
+        ['OS=="linux"', {
+          'conditions': [
+            ['use_aura==1', {
+              'dependencies': [
+                '../build/linux/system.gyp:dbus',
+                '../build/linux/system.gyp:fontconfig',
+                '../dbus/dbus.gyp:dbus',
+              ],
+            }],
+            # x11 build
+            ['use_x11==1', {
+              'dependencies': [
+                '../build/linux/system.gyp:x11',
+              ],
+            }],
           ],
         }],
         ['safe_browsing==1', {
           'defines': [
             'FULL_SAFE_BROWSING',
           ],
         }],
         ['safe_browsing==2', {
           'defines': [
             'MOBILE_SAFE_BROWSING',
@@ skipping 178 matching lines @@
           'variables': {
             'proto_in_dir': 'browser/chromeos/contacts',
             'proto_out_dir': 'chrome/browser/chromeos/contacts',
           },
           'includes': [ '../build/protoc.gypi' ]
         },
       ],
     },],  # 'chromeos=1'
   ],  # 'conditions'
 }