SkAlpha constant defs

R=edisonn@google.com, vandebo@chromium.org, reed@google.com

Author: richardlin@chromium.org

Review URL: https://chromiumcodereview.appspot.com/19592014

git-svn-id: http://skia.googlecode.com/svn/trunk@10195 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed