Remove the unused _WKBackForwardListDidChangeNotification.

Reviewed by Anders Carlsson.

* UIProcess/API/Cocoa/WKBackForwardList.mm:
* UIProcess/API/Cocoa/WKBackForwardListInternal.h:
* UIProcess/API/Cocoa/WKBackForwardListPrivate.h: Removed.
* UIProcess/Cocoa/NavigationState.h:
* UIProcess/Cocoa/NavigationState.mm:
(WebKit::NavigationState::LoaderClient::didChangeBackForwardList): Deleted.
* WebKit2.xcodeproj/project.pbxproj:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@170101 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Unreviewed, rolling out r170099.
https://bugs.webkit.org/show_bug.cgi?id=134031

Introduced a layouttest failure to the mac bots (Requested by
bradeeoh on #webkit).

Reverted changeset:

"Mark mathml/wbr-in-mroot-crash.html as "Timeout Pass""
https://bugs.webkit.org/show_bug.cgi?id=130353
http://trac.webkit.org/changeset/170099

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@170102 268f45cc-cd09-0410-ab3c-d52691b4dbfc