Just like other events, WebGLContextEvent should have a constructor. See this bug for reference: <http://www.khronos.org/bugzilla/show_bug.cgi?id=550>
Spec: http://www.khronos.org/registry/webgl/specs/latest/#5.14
Created attachment 116589 [details] Patch
Comment on attachment 116589 [details] Patch Clearing flags on attachment: 116589 Committed r101183: <http://trac.webkit.org/changeset/101183>
All reviewed patches have been landed. Closing bug.