effects: Replaces uses of GrAssert with SkASSERT.

This is the first step on migrating from GrAssert to SkASSERT as requested by
Brian.

R=bsalomon@google.com, robertphillips@google.com, scroggo@google.com

Author: tfarina@chromium.org

Review URL: https://chromiumcodereview.appspot.com/22418006

git-svn-id: http://skia.googlecode.com/svn/trunk@10706 2bbb7eff-a529-9590-31e7-b0007b416f81
8 files changed