Disable window occlusion notifications for App Store on Mac.

Disable window occlusion notifications for App Store on Mac.
https://bugs.webkit.org/show_bug.cgi?id=110417

Patch by Kiran Muppala <cmuppala@apple.com> on 2013-02-20
Reviewed by Simon Fraser.

Temporary fix to workaround issues with window occlusion notifications
in App Store.

* UIProcess/API/mac/WKView.mm:
(+[WKView _registerWindowOcclusionNotificationHandlers]): Return early
if the main bundle identifier matches that of App Store.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@143552 268f45cc-cd09-0410-ab3c-d52691b4dbfc