REGRESSION (r156291): TileController tiles don't always repaint when they resize
https://bugs.webkit.org/show_bug.cgi?id=124796

Reviewed by Simon Fraser.

In removing platformCALayerDidCreateTiles, r156291 also removed
the call to setNeedsDisplay when tiles are resized, without
putting it somewhere else.

* platform/graphics/ca/mac/TileController.mm:
(WebCore::TileController::setNeedsDisplay):
Use hasStaleContent when invalidating a whole tile, just
like we do for partial tile repaints.

(WebCore::TileController::setTileNeedsDisplayInRect):
Mark hasStaleContent for any unparented layers, so they'll be painted
when they are reparented.

(WebCore::TileController::ensureTilesForRect):
Invalidate the whole tile when it changes size.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@159732 268f45cc-cd09-0410-ab3c-d52691b4dbfc