Having updated the documentation of GrCustomStage to argue that all custom stages must be
immutable, this CL makes that true for ConvolutionEffect.

http://codereview.appspot.com/6398043/



git-svn-id: http://skia.googlecode.com/svn/trunk@4613 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed