Move _ignoresNonWheelMouseEvents implementation to WKView(Private)
https://bugs.webkit.org/show_bug.cgi?id=138487

Patch by Conrad Shultz <conrad_shultz@apple.com> on 2014-11-09
Reviewed by Dan Bernstein.

Relocate some methods that should have been in a category implementation.

* UIProcess/API/mac/WKView.mm:
(-[WKView _setIgnoresNonWheelMouseEvents:]):
(-[WKView _ignoresNonWheelMouseEvents]):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@175790 268f45cc-cd09-0410-ab3c-d52691b4dbfc