Few methods in WebGLRenderingContext.idl have incorrect signatures
https://bugs.webkit.org/show_bug.cgi?id=110305

Reviewed by Kentaro Hara.

* html/canvas/WebGLRenderingContext.idl:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@143432 268f45cc-cd09-0410-ab3c-d52691b4dbfc