BUG=269
TESTED=c:\intelsde\sde -ast -hsw -- out\release\libyuv_unittest.exe --gtest_filter=*I420ToBGRA*
R=brucedawson@google.com, harryjin@google.com, magjed@chromium.org

Review URL: https://webrtc-codereview.appspot.com/26869004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1127 16f28f9a-4ce2-e073-06de-1de4eb20be90