https://bugs.webkit.org/show_bug.cgi?id=127300
<rdar://problem/15861296>

Reviewed by Dan Bernstein.

This is the first step towards moving handling of user scripts and style sheets from
the page group to a separate objects and ultimately make them be settable per page instead of per page group.

* CMakeLists.txt:
* GNUmakefile.list.am:
* WebCore.vcxproj/WebCore.vcxproj:
* WebCore.vcxproj/WebCore.vcxproj.filters:
* WebCore.xcodeproj/project.pbxproj:
* page/UserContentController.cpp: Added.
(WebCore::UserContentController::create):
(WebCore::UserContentController::UserContentController):
(WebCore::UserContentController::~UserContentController):
* page/UserContentController.h: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@162372 268f45cc-cd09-0410-ab3c-d52691b4dbfc