Fix event targetting bugs by using paint layers in GetFrameForPoint, testing for visibility, and trying GetFrameForPoint on additional views if one fails. r=joki@netscape.com(, hyatt@netscape.com) b=12232,20051,21304,24474,26785, and remaining issues from 23161.

git-svn-id: svn://10.0.0.236/trunk@63689 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/layout/generic/nsViewportFrame.cpp

@@ -55,6 +55,10 @@ public:
   NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
                                  nsIAtom*        aListName,
                                  nsIFrame*       aChildList);
+  NS_IMETHOD GetFrameForPoint(nsIPresContext* aPresContext,
+                              const nsPoint& aPoint, 
+                              nsFramePaintLayer aWhichLayer,
+                              nsIFrame**     aFrame);
   NS_IMETHOD AppendFrames(nsIPresContext* aPresContext,
                           nsIPresShell&   aPresShell,
                           nsIAtom*        aListName,
@@ -161,6 +165,16 @@ ViewportFrame::SetInitialChildList(nsIPresContext* aPresContext,
   return rv;
 }
 
+NS_IMETHODIMP
+ViewportFrame::GetFrameForPoint(nsIPresContext* aPresContext,
+                                   const nsPoint& aPoint, 
+                                   nsFramePaintLayer aWhichLayer,
+                                   nsIFrame**     aFrame)
+{
+  // this should act like a block, so we need to override
+  return GetFrameForPointUsing(aPresContext, aPoint, nsnull, aWhichLayer, (aWhichLayer == NS_FRAME_PAINT_LAYER_BACKGROUND), aFrame);
+}
+
 NS_IMETHODIMP
 ViewportFrame::AppendFrames(nsIPresContext* aPresContext,
                             nsIPresShell&   aPresShell,