DOMEvents.h should include DOMProgressEvent.h
https://bugs.webkit.org/show_bug.cgi?id=106250

Reviewed by Sam Weinig.

DOMProgressEvent.h is already installed as a public header, so it should also be included by DOMEvents.h.

* bindings/objc/DOMEvents.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@138992 268f45cc-cd09-0410-ab3c-d52691b4dbfc