Optimize building gradient cache for when we know alpha is always 0xFF.
remove old build guard for dithering.
Review URL: https://codereview.appspot.com/7309064

git-svn-id: http://skia.googlecode.com/svn/trunk@7678 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed