Fix the bug of multiple overlays.

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',
     # These files lists are shared with the GN build.
     'ash_sources': [
@@ skipping 671 matching lines @@
       'test/shelf_view_test_api.cc',
       'test/shelf_view_test_api.h',
       'test/shell_test_api.cc',
       'test/shell_test_api.h',
       'test/status_area_widget_test_helper.cc',
       'test/status_area_widget_test_helper.h',
       'test/test_activation_delegate.cc',
       'test/test_activation_delegate.h',
       'test/test_lock_state_controller_delegate.cc',
       'test/test_lock_state_controller_delegate.h',
+      'test/test_overlay_delegate.cc',
+      'test/test_overlay_delegate.h',
       'test/test_screenshot_delegate.cc',
       'test/test_screenshot_delegate.h',
       'test/test_session_state_delegate.cc',
       'test/test_session_state_delegate.h',
       'test/test_shelf_delegate.cc',
       'test/test_shelf_delegate.h',
       'test/test_shelf_item_delegate.cc',
       'test/test_shelf_item_delegate.h',
       'test/test_shell_delegate.cc',
       'test/test_shell_delegate.h',
@@ skipping 151 matching lines @@
       'wm/video_detector_unittest.cc',
       'wm/window_animations_unittest.cc',
       'wm/window_cycle_controller_unittest.cc',
       'wm/window_manager_unittest.cc',
       'wm/window_modality_controller_unittest.cc',
       'wm/window_positioner_unittest.cc',
       'wm/window_state_unittest.cc',
       'wm/window_util_unittest.cc',
       'wm/maximize_mode/workspace_backdrop_delegate.cc',
       'wm/maximize_mode/workspace_backdrop_delegate.h',
+      'wm/overlay_event_filter_unittest.cc',
       'wm/workspace/magnetism_matcher_unittest.cc',
       'wm/workspace/multi_window_resize_controller_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',
       'wm/workspace_controller_test_helper.cc',
       'wm/workspace_controller_test_helper.h',
       'wm/workspace_controller_unittest.cc',
@@ skipping 375 matching lines @@
       'conditions': [
         ['chromeos==1', {
           'dependencies': [
             '../ui/display/display.gyp:display',
           ],
         }],
       ],
     },
   ],
 }