Disable dithering of const paints

... except for 565.

Change-Id: I8ab633661c54583478234a46942ef804eb74a619
Reviewed-on: https://skia-review.googlesource.com/19880
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Herb Derby <herb@google.com>
4 files changed