root/chrome/browser/ui/views/message_center/

[..]
  1. message_center_frame_view.cc
  2. message_center_frame_view.h
  3. message_center_widget_delegate.cc
  4. message_center_widget_delegate.h
  5. web_notification_tray.cc
  6. web_notification_tray.h
  7. web_notification_tray_browsertest.cc
  8. web_notification_tray_win.cc
[..]