Complete the implementation of the faster blur; now supports all blur styles and matches the boxfilter approximation visually.  Also change the interpretation of the blur radius to be sigma/2; need to add SK_IGNORE_BLUR_RADIUS_CORRECTNESS to chromium GYP to avoid immediate layout test failures over there.

Review URL: https://codereview.appspot.com/7307076

git-svn-id: http://skia.googlecode.com/svn/trunk@7793 2bbb7eff-a529-9590-31e7-b0007b416f81
4 files changed