[chromium] Make tiled layer's tiler always exist
Created attachment 120706 [details] Patch
This is a refactoring that I ended up doing to fix bug 56591 and wanted to land separately. That bug would introduce some additional CCLayerTilingData members that I didn't want to also shadow in TiledLayerChromium and then have to remember to set again whenever the tiler got recreated. I think this ends up being much cleaner.
Comment on attachment 120706 [details] Patch Cool! R=me
Committed r103944: <http://trac.webkit.org/changeset/103944>