BlendTest: implicit casts -> explicit casts

BUG=skia:

Committed: http://code.google.com/p/skia/source/detail?r=13595

R=reed@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/181503003

git-svn-id: http://skia.googlecode.com/svn/trunk@13602 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed