Tray elements behave appropriately on the multiple signin screen (more like lock screen)

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 168 matching lines @@
       'root_window_controller.h',
       'root_window_settings.cc',
       'root_window_settings.h',
       'rotator/screen_rotation.cc',
       'rotator/screen_rotation.h',
       'scoped_target_root_window.cc',
       'scoped_target_root_window.h',
       'screen_util.cc',
       'screen_util.h',
       'screenshot_delegate.h',
+      'session/session_state_delegate.cc',
       'session/session_state_delegate.h',
       'session/session_state_observer.cc',
       'session/session_state_observer.h',
       'shelf/app_list_button.cc',
       'shelf/app_list_button.h',
       'shelf/app_list_shelf_item_delegate.cc',
       'shelf/app_list_shelf_item_delegate.h',
       'shelf/background_animator.cc',
       'shelf/background_animator.h',
       'shelf/overflow_bubble.cc',
@@ skipping 1047 matching lines @@
       'conditions': [
         ['chromeos==1', {
           'dependencies': [
             '../ui/display/display.gyp:display',
           ],
         }],
       ],
     },
   ],
 }