Fix ConvertToI420() to properly delete temporary array when rotating result. When rotating an image ConvertToI420() allocates a temporary buffer using new[], but then attempts to delete it using delete instead of delete[].This issue is not the root cause of the referenced bug, but it needs to be addressed in order to fix that bug.
BUG=crbug.com/306876
TESTED=try bots
R=wuwang@google.com

Review URL: https://webrtc-codereview.appspot.com/4129005

git-svn-id: http://libyuv.googlecode.com/svn/trunk@866 16f28f9a-4ce2-e073-06de-1de4eb20be90