Discard scratch render targets before reusing them.

R=robertphillips@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/225183012

git-svn-id: http://skia.googlecode.com/svn/trunk@14075 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed