Only support left/right maximizing at 50% width when the --ash-enable-alternate-caption-button

ash/ash.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,
     'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/chrome',
   },
   'includes': [
@@ skipping 756 matching lines @@
         'wm/window_cycle_controller_unittest.cc',
         'wm/window_manager_unittest.cc',
         'wm/window_modality_controller_unittest.cc',
         'wm/window_util_unittest.cc',
         'wm/workspace_controller_test_helper.cc',
         'wm/workspace_controller_test_helper.h',
         'wm/workspace_controller_unittest.cc',
         'wm/workspace/frame_caption_button_container_view_unittest.cc',
         'wm/workspace/magnetism_matcher_unittest.cc',
         'wm/workspace/multi_window_resize_controller_unittest.cc',
+        'wm/workspace/snap_sizer_unittest.cc',
         'wm/workspace/workspace_event_handler_test_helper.cc',
         'wm/workspace/workspace_event_handler_test_helper.h',
         'wm/workspace/workspace_event_handler_unittest.cc',
         'wm/workspace/workspace_layout_manager_unittest.cc',
         'wm/workspace/workspace_window_resizer_unittest.cc',
       ],
       'conditions': [
         ['OS=="win"', {
           'sources/': [
             # TODO(zork): fix this test to build on Windows. See: crosbug.com/26906
@@ skipping 140 matching lines @@
             'shell/cocoa/app-Info.plist',
           ],
           'xcode_settings': {
             'INFOPLIST_FILE': 'shell/cocoa/app-Info.plist',
           },
         }],
       ],
     },
   ],
 }