Loading sites that have compositing layers with WebKit2 can crash because RenderLayerCompositor::enableCompositingMode sometimes gets re-entered when setting up layers. This only happens with a 32 bit build because it depends on plugins (like Flash) getting a layer. It is also timing related so it doesn't always happen.
rdar://problem/8975923
Created attachment 82243 [details] Patch
Committed r78425: <http://trac.webkit.org/changeset/78425>