Two changes to desktop aura for tooltips:

ui/views/views.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,
   },
   'target_defaults': {
     'conditions': [
       ['use_aura==1', {
@@ skipping 372 matching lines @@
         'widget/desktop_aura/desktop_root_window_host_win.h',
         'widget/desktop_aura/desktop_root_window_host_x11.cc',
         'widget/desktop_aura/desktop_root_window_host_x11.h',
         'widget/desktop_aura/desktop_screen.h',
         'widget/desktop_aura/desktop_screen_ozone.cc',
         'widget/desktop_aura/desktop_screen_position_client.cc',
         'widget/desktop_aura/desktop_screen_position_client.h',
         'widget/desktop_aura/desktop_screen_win.cc',
         'widget/desktop_aura/desktop_screen_win.h',
         'widget/desktop_aura/desktop_screen_x11.cc',
+        'widget/desktop_aura/scoped_tooltip_client.cc',
+        'widget/desktop_aura/scoped_tooltip_client.h',
         'widget/desktop_aura/x11_desktop_handler.cc',
         'widget/desktop_aura/x11_desktop_handler.h',
         'widget/desktop_aura/x11_desktop_window_move_client.cc',
         'widget/desktop_aura/x11_desktop_window_move_client.h',
         'widget/desktop_aura/x11_whole_screen_move_loop.cc',
         'widget/desktop_aura/x11_whole_screen_move_loop.h',
         'widget/desktop_aura/x11_whole_screen_move_loop_delegate.h',
         'widget/desktop_aura/x11_window_event_filter.cc',
         'widget/desktop_aura/x11_window_event_filter.h',
         'widget/drop_helper.cc',
@@ skipping 651 matching lines @@
           'sources/': [
             # This is needed because the aura rule strips it from the default
             # sources list.
             ['include', '^../../content/app/startup_helper_win.cc'],
           ],
         }],
       ],
     },  # target_name: views_examples_with_content_exe
   ],
 }