(SSE2) acceleration for rectangular opaque erases.
15% speedup for rectangles < 31 px wide, 5% for larger.

http://codereview.appspot.com/5843050/



git-svn-id: http://skia.googlecode.com/svn/trunk@3423 2bbb7eff-a529-9590-31e7-b0007b416f81
8 files changed