Reviewed by Mitz Pettel RTL

        Preparation for upcoming work making LocalStorage persistent.

        - Create the LocalStorage object for a PageGroup the moment the first Page is added to it
          The Settings of the first Page define what persistent path the LocalStorage will use
        - Add a Frame argument for the LocalStorageArea request - this will allow a client object
          to be queried before the LocalStorageArea is established

        * page/DOMWindow.cpp:
        (WebCore::DOMWindow::localStorage):

        * page/PageGroup.cpp:
        (WebCore::PageGroup::addPage):
        (WebCore::PageGroup::localStorage):

        * storage/LocalStorage.cpp:
        (WebCore::LocalStorage::LocalStorage): Take the path as a constructor argument.  Deep copy
          the path as it will be used from another thread.
        (WebCore::LocalStorage::storageArea):
        * storage/LocalStorage.h:
        (WebCore::LocalStorage::create):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@32899 268f45cc-cd09-0410-ab3c-d52691b4dbfc