Web Inspector: take page scale factor into account when updating overlay.
https://bugs.webkit.org/show_bug.cgi?id=108831

Reviewed by Vsevolod Vlasov.

Otherwise, the ports that use page scale factor have broken overlay.

* inspector/InspectorOverlay.cpp:
(WebCore::InspectorOverlay::update):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141772 268f45cc-cd09-0410-ab3c-d52691b4dbfc