Applied patch from Ticket #9563. Use just the rectangle of the widget with the focus...

Applied patch from Ticket #9563.  Use just the rectangle of the widget with the focus when deciding if scrolling is needed, instead of the rect of the parent of the widget/child of the target window.  This fixes some flickering when a panel of widgets is used inside the scrolled window, and also a total lack of scrolling if the focused widget is out of view but the upper-left corner of the panel is in view.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@54552 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775