Provide private API to request the global context for a specific world.
Used to initialize parameters on the global object.

Patch by Gavin Barraclough <barraclough@apple.com> on 2009-10-23
Reviewed by Geoff Garen.

WebCore: 

* bindings/js/ScriptController.cpp:
(WebCore::ScriptController::globalObject):
* bindings/js/ScriptController.h:

WebKit/mac: 

* WebView/WebFramePrivate.h:
* WebView/WebFrame.mm:
(-[WebFrame contextForWorldID:]):

WebKit/win: 

* WebFrame.cpp:
(WebFrame::contextForWorldID):
* WebFrame.h:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@50012 268f45cc-cd09-0410-ab3c-d52691b4dbfc