SkHitBox is a class that determines which draw command is associated with the pixel located at x,y. By calculating a single point instead of the entire bitmap at once there is no visible performance slowdown.
Review URL: https://codereview.appspot.com/6350098
git-svn-id: http://skia.googlecode.com/svn/trunk@4565 2bbb7eff-a529-9590-31e7-b0007b416f81
