Apply intersect rects to earlier clip elements and skip rects when possible.

R=robertphillips@google.com
Review URL: https://codereview.appspot.com/6814105

git-svn-id: http://skia.googlecode.com/svn/trunk@6351 2bbb7eff-a529-9590-31e7-b0007b416f81
4 files changed