Add stroked ovals and CircleEdgeEffect.

Adds some optimizations to the circle and ellipse shaders, static effect 
instances for their GrEffects, and some minor changes to GrDrawState::setEffect
to make GrEffect setup faster.


git-svn-id: http://skia.googlecode.com/svn/trunk@8238 2bbb7eff-a529-9590-31e7-b0007b416f81
11 files changed