BUG=http://code.google.com/p/angleproject/issues/detail?id=275
TEST=WebGL conformance suite
TBR=nicolas
Review URL: http://codereview.appspot.com/5520049

git-svn-id: https://angleproject.googlecode.com/svn/trunk@938 736b8ea6-26fd-11df-bfd4-992fa37f6226