Wrap GrEffects in GrEffectPtr.

This is the first step towards automatic recycling of scratch resouces in the cache via ref-cnts.

R=robertphillips@google.com
Review URL: https://codereview.appspot.com/7092061

git-svn-id: http://skia.googlecode.com/svn/trunk@7222 2bbb7eff-a529-9590-31e7-b0007b416f81
48 files changed