Attempt 3 at:

ui/aura_shell/aura_shell.gyp

 # Copyright (c) 2011 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,
   },
 
   'targets': [
@@ skipping 117 matching lines @@
         '../../base/base.gyp:test_support_base',
         '../../chrome/chrome_resources.gyp:packed_resources',
         '../../build/temp_gyp/googleurl.gyp:googleurl',
         '../../skia/skia.gyp:skia',
         '../../testing/gtest.gyp:gtest',
         '../../third_party/icu/icu.gyp:icui18n',
         '../../third_party/icu/icu.gyp:icuuc',
         '../aura/aura.gyp:aura',
         '../aura/aura.gyp:test_support_aura',
         '../gfx/compositor/compositor.gyp:compositor_test_support',
-        '../gfx/compositor/compositor.gyp:test_compositor',
         '../ui.gyp:gfx_resources',
         '../ui.gyp:ui',
         '../ui.gyp:ui_resources',
         '../ui.gyp:ui_resources_standard',
         '../views/views.gyp:views',
         'aura_shell',
       ],
       'sources': [
         'default_container_layout_manager_unittest.cc',
         'root_window_event_filter_unittest.cc',
@@ skipping 14 matching lines @@
         'test/aura_shell_test_base.h',
         'toplevel_layout_manager_unittest.cc',
         'toplevel_window_event_filter_unittest.cc',
         'workspace_controller_unittest.cc',
         'workspace/workspace_manager_unittest.cc',
 
         '<(SHARED_INTERMEDIATE_DIR)/ui/gfx/gfx_resources.rc',
         '<(SHARED_INTERMEDIATE_DIR)/ui/ui_resources/ui_resources.rc',
         '<(SHARED_INTERMEDIATE_DIR)/ui/ui_resources_standard/ui_resources_standard.rc',
       ],
+      'conditions': [
+        ['use_webkit_compositor==1', {
+          'dependencies': [
+            '../gfx/compositor/compositor.gyp:compositor',
+          ],
+        }, { # use_webkit_compositor!=1
+          'dependencies': [
+            '../gfx/compositor/compositor.gyp:test_compositor',
+          ],
+        }],
+      ],
     },
     {
       'target_name': 'aura_shell_exe',
       'type': 'executable',
       'dependencies': [
         '../../base/base.gyp:base',
         '../../base/base.gyp:base_i18n',
         '../../chrome/chrome_resources.gyp:packed_resources',
         '../../skia/skia.gyp:skia',
         '../../third_party/icu/icu.gyp:icui18n',
@@ skipping 19 matching lines @@
         'examples/widgets.cc',
         'examples/window_type_launcher.cc',
         'examples/window_type_launcher.h',
         '<(SHARED_INTERMEDIATE_DIR)/ui/gfx/gfx_resources.rc',
         '<(SHARED_INTERMEDIATE_DIR)/ui/ui_resources/ui_resources.rc',
         '<(SHARED_INTERMEDIATE_DIR)/ui/ui_resources_standard/ui_resources_standard.rc',
       ],
     },
   ],
 }