https://bugs.webkit.org/show_bug.cgi?id=127317
<rdar://problem/15861296>

Reviewed by Andreas Kling.

Move handling of user scripts from PageGroup to UserContentController.

* page/Frame.cpp:
(WebCore::Frame::injectUserScripts):
* page/PageGroup.cpp:
(WebCore::PageGroup::addUserScriptToWorld):
(WebCore::PageGroup::removeUserScriptFromWorld):
(WebCore::PageGroup::removeUserScriptsFromWorld):
(WebCore::PageGroup::removeAllUserContent):
* page/PageGroup.h:
* page/UserContentController.cpp:
(WebCore::UserContentController::addUserScript):
(WebCore::UserContentController::removeUserScript):
(WebCore::UserContentController::removeUserScripts):
(WebCore::UserContentController::removeAllUserContent):
* page/UserContentController.h:
(WebCore::UserContentController::userScripts):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@162384 268f45cc-cd09-0410-ab3c-d52691b4dbfc