Unreviewed, rolling out r150034.

Unreviewed, rolling out r150034.
http://trac.webkit.org/changeset/150034
https://bugs.webkit.org/show_bug.cgi?id=116257

This work around doesn't work due to another bug NSUndoManager
has (Requested by rniwa on #webkit).

Patch by Commit Queue <commit-queue@webkit.org> on 2013-05-16

Source/WebKit/mac:

* WebCoreSupport/WebEditorClient.mm:
(WebEditorClient::registerUndoOrRedoStep):

Source/WebKit2:

* UIProcess/API/mac/PageClientImpl.mm:
(WebKit::PageClientImpl::registerEditCommand):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@150230 268f45cc-cd09-0410-ab3c-d52691b4dbfc