Add NativeWebWheelEvent class
This will be needed soon when we start notifying the UI process that a mouse wheel event wasn't handled by WebKit.
Created attachment 92269 [details]
Committed r85756: <http://trac.webkit.org/changeset/85756>
Steve Falkenburg pointed out that I misspelled the svn:eol-style property on NativeWebWheelEventMac.mm, which I fixed in http://trac.webkit.org/changeset/85764