root/chrome/browser/ui/views/panels/

1. panel_frame_view.cc
2. panel_frame_view.h
3. panel_stack_view.cc
4. panel_stack_view.h
5. panel_view.cc
6. panel_view.h
7. panel_view_browsertest.cc
8. taskbar_window_thumbnailer_win.cc
9. taskbar_window_thumbnailer_win.h