BUG=271
TESTED=out\release\libyuv_unittest --gtest_filter=**R*ToARGB*
R=johannkoenig@google.com, ryanpetrie@google.com

Review URL: https://webrtc-codereview.appspot.com/2361004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@807 16f28f9a-4ce2-e073-06de-1de4eb20be90