Remove -enterFrame: and -leaveFrame from WebScriptDebugger

    Remove -enterFrame: and -leaveFrame from WebScriptDebugger

        Reviewed by Kevin M.

        * WebView/WebCoreScriptDebuggerImp.h: Changed to store m_topCallFrame
        in a RetainPtr, now that WebCoreScriptDebuggerImp is in charge of its
        lifetime.
        * WebView/WebCoreScriptDebuggerImp.mm:
          - Added declaration of -[WebScriptCallFrame
            _initWithGlobalObject:caller:state:].
          - Changed most uses of m_topCallFrame to m_topCallFrame.get()
        (WebCoreScriptDebuggerImp::WebCoreScriptDebuggerImp): Removed
        now-unnecessary initialization of m_topCallFrame.
        (WebCoreScriptDebuggerImp::callEvent): Replaced call to enterFrame:
        with its implementation. The one difference between this
        implementation and the old enterFrame: method is that we don't hand
        our reference to m_topCallFrame to _initWithGlobalObject: -- that
        method must now retain the passed-in WebScriptCallFrame manually.
        (WebCoreScriptDebuggerImp::atStatement):
        (WebCoreScriptDebuggerImp::returnEvent): Replaced call to leaveFrame
        with its implementation.
        (WebCoreScriptDebuggerImp::exception):
        * WebView/WebScriptDebugDelegate.mm: Removed declaration of
        -[WebScriptCallFrame _initWithGlobalObject:caller:state:].
        (-[WebScriptCallFrame _initWithGlobalObject:caller:state:]): Changed
        to retain the passed-in caller.
        * WebView/WebScriptDebugDelegatePrivate.h:
          - Removed _current ivar
          - Removed enterFrame:/leaveFrame declarations.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@30834 268f45cc-cd09-0410-ab3c-d52691b4dbfc