Add flipped gradient branch to two point conical gradient

BUG=skia:

Committed: http://code.google.com/p/skia/source/detail?r=14235

R=bsalomon@google.com

Author: egdaniel@google.com

Review URL: https://codereview.chromium.org/227623004

git-svn-id: http://skia.googlecode.com/svn/trunk@14271 2bbb7eff-a529-9590-31e7-b0007b416f81
7 files changed