classes from r3726 so they can be used. Does not implement any actual
effect stages.
Has one large known bug: if custom stages are provided, GrSamplerState
comparisons will break; this should preserve correct drawing, but decrease
performance - among other things, we'll break draw batching. To fix this
we'll need a RTTI system for GrCustomState objects, and we'll need to change
the GrSamplerState comparison from a memcmp to something that also does a
deep type-sensitive compare of any GrCustomState objects present.
http://codereview.appspot.com/6074043/
git-svn-id: http://skia.googlecode.com/svn/trunk@3742 2bbb7eff-a529-9590-31e7-b0007b416f81
07eecdca3e