stop using bitmap-filter flags outside of paint itself, as a step towards really changing them into an enum

BUG=

Review URL: https://codereview.chromium.org/19825002

git-svn-id: http://skia.googlecode.com/svn/trunk@10240 2bbb7eff-a529-9590-31e7-b0007b416f81
16 files changed