athena: Add a test for split-view controller.

athena/athena.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': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 158 matching lines @@
         'athena_lib',
         'athena_test_support',
         'resources/athena_resources.gyp:athena_pak',
       ],
       'sources': [
         'test/athena_unittests.cc',
         'activity/activity_manager_unittest.cc',
         'home/home_card_unittest.cc',
         'input/accelerator_manager_unittest.cc',
         'screen/screen_manager_unittest.cc',
+        'wm/split_view_controller_unittest.cc',
         'wm/window_manager_unittest.cc',
       ],
     }
   ],
 }