GTK build fix: Have a dummy aura_builder target even with use_aura=0.

build/all.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': {
     # A hook that can be overridden in other repositories to add additional
     # compilation targets to 'All'. Only used on Android.
     'android_app_targets%': [],
   },
@@ skipping 1181 matching lines @@
               ],
             }],
             ['chromeos==1', {
               'dependencies': [
                 '../chromeos/chromeos.gyp:chromeos_unittests',
               ],
             }],
           ],
         },
       ],  # targets
+    }, {
+      # TODO(thakis): Remove this once the linux gtk bot no longer references
+      # it (probably after the first aura release on linux), see r249162
+      'targets': [
+        {
+          'target_name': 'aura_builder',
+          'type': 'none',
+        },
+      ],  # targets
     }], # "use_aura==1"
     ['test_isolation_mode != "noop"', {
       'targets': [
         {
           'target_name': 'chromium_swarm_tests',
           'type': 'none',
           'dependencies': [
             '../base/base.gyp:base_unittests_run',
             '../chrome/chrome.gyp:browser_tests_run',
             '../chrome/chrome.gyp:interactive_ui_tests_run',
             '../chrome/chrome.gyp:sync_integration_tests_run',
             '../chrome/chrome.gyp:unit_tests_run',
             '../net/net.gyp:net_unittests_run',
           ],
         }, # target_name: chromium_swarm_tests
       ],
     }],
   ], # conditions
 }