Bug 396185 - Make nsIFrame derivatives and helper abstract classes use a different dynamic-cast system than nsISupports:

* we know all types frames may be cast to at compile time, so instead of extensible GUID IIDs, use a big enum (see nsQueryFrame::FrameIID)
* eliminate all vestiges of refcounting, since frames aren't refcounted

Some frames (SVG frames in particular) still implement nsISupports-derived interfaces, for example nsISVGValue. There is a FrameIID for nsISVGValue that lets you go from a frame to the XPCOM interface, but you can't query back.

r+sr=roc

This patch locally causes two REFTEST-UNEXPECTED-PASS for Bidi stuff. It's possible that I accidentally fixed a bug, but I'm not sure, so I'm going to wait for the tinderboxes to confirm my local results.

layout/xul/base/src/nsMenuFrame.cpp

@@ -168,25 +168,10 @@ NS_NewMenuFrame(nsIPresShell* aPresShell, nsStyleContext* aContext, PRUint32 aFl
   return it;
 }
 
-NS_IMETHODIMP_(nsrefcnt) 
-nsMenuFrame::AddRef(void)
-{
-  return NS_OK;
-}
-
-NS_IMETHODIMP_(nsrefcnt)
-nsMenuFrame::Release(void)
-{
-    return NS_OK;
-}
-
-//
-// QueryInterface
-//
-NS_INTERFACE_MAP_BEGIN(nsMenuFrame)
-  NS_INTERFACE_MAP_ENTRY(nsIMenuFrame)
-  NS_INTERFACE_MAP_ENTRY(nsIScrollableViewProvider)
-NS_INTERFACE_MAP_END_INHERITING(nsBoxFrame)
+NS_QUERYFRAME_HEAD(nsMenuFrame)
+  NS_QUERYFRAME_ENTRY(nsIMenuFrame)
+  NS_QUERYFRAME_ENTRY(nsIScrollableViewProvider)
+NS_QUERYFRAME_TAIL_INHERITING(nsBoxFrame)
 
 //
 // nsMenuFrame cntr
@@ -770,7 +755,7 @@ nsMenuFrame::DoLayout(nsBoxLayoutState& aState)
 
     nsRect bounds(mPopupFrame->GetRect());
 
-    nsCOMPtr<nsIScrollableFrame> scrollframe(do_QueryInterface(child));
+    nsIScrollableFrame *scrollframe = do_QueryFrame(child);
     if (scrollframe &&
         scrollframe->GetScrollbarStyles().mVertical == NS_STYLE_OVERFLOW_AUTO) {
       if (bounds.height < prefSize.height) {