When compositing layers are used on Windows, a single large layer is created for the root of the rendering tree. If the markup involves creating large offscreen areas, WebKit can end up allocating a lot of memory.
Instead, we should use the tiled drawing logic for the background layer so that we can limit the amount of memory used.
Created attachment 261505 [details]
Comment on attachment 261505 [details]
Committed r189974: <http://trac.webkit.org/changeset/189974>