[WK2] The root and page overlay layers should be the size of the view, not the content
https://bugs.webkit.org/show_bug.cgi?id=110660
<rdar://problem/13096456>

Reviewed by Simon Fraser.

Use the view size for the size of the root and page overlay layers.
For one, we never update these layers' sizes when the content size changes, causing size mismatches.
In addition, there's no reason an overlay shouldn't be able to draw outside of the bounds of the content.

* WebProcess/WebPage/mac/TiledCoreAnimationDrawingArea.mm:
(WebKit::TiledCoreAnimationDrawingArea::updateGeometry):
(WebKit::TiledCoreAnimationDrawingArea::createPageOverlayLayer):

* WebCore.exp.in:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@143816 268f45cc-cd09-0410-ab3c-d52691b4dbfc