Two WKWebView internal methods are implemented in a category
https://bugs.webkit.org/show_bug.cgi?id=138728

Reviewed by Tim HOrton.

Moved the implementations from the category to the class.

* UIProcess/API/Cocoa/WKWebView.mm:
(-[WKWebView _ignoresNonWheelMouseEvents]):
(-[WKWebView _setIgnoresNonWheelMouseEvents:]):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@176116 268f45cc-cd09-0410-ab3c-d52691b4dbfc