Removing them is a little trouble, but worth it going forward.
The pattern of creating a "CachedFrameBase" as the interface CachedFrame provides to FrameLoader
was suggested by Darin Adler.

Reviewed by Darin Adler.

No new tests. (No change in behavior)

Make CachedFrame inherit privately from CachedFrameBase, which becomes the interface FrameLoader uses:
* history/CachedFrame.cpp:
(WebCore::CachedFrameBase::CachedFrameBase):
(WebCore::CachedFrameBase::~CachedFrameBase):
(WebCore::CachedFrameBase::restore):
(WebCore::CachedFrame::CachedFrame):
(WebCore::CachedFrame::openInFrameLoader):
* history/CachedFrame.h:
(WebCore::CachedFrameBase::document):
(WebCore::CachedFrameBase::view):
(WebCore::CachedFrameBase::domWindow):
(WebCore::CachedFrame::create):
(WebCore::CachedFrame::documentLoader):
(WebCore::CachedFrame::mousePressNode):

Call the new ::openInFrameLoader() method on the CachedFrame, as CachedFrameBase is now the only
thing capable of interacting with FrameLoader::open(CachedFrameBase):
* history/CachedPage.cpp:
(WebCore::CachedPage::restore):
* history/CachedPage.h:
(WebCore::CachedPage::documentLoader):

Make ::open(CachedFrame) public, and change it to ::open(CachedFrameBase):
* loader/FrameLoader.cpp:
(WebCore::FrameLoader::open):
* loader/FrameLoader.h:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@47989 268f45cc-cd09-0410-ab3c-d52691b4dbfc