Sometimes shadows draw via ShadowBlur.cpp are corrupted, containing contents of old shadows. The checks in matchesLastShadow() don't consider when m_layerSize changes and thus some of the old content of the scratch buffer might be drawn. This patch is to store the last m_layerSize value and make sure that matches as well.
Created attachment 127467 [details]
Committed r108008: <http://trac.webkit.org/changeset/108008>