Adding two files. Tree might go red, since i forgot to add these.

layout/xul/base/src/nsTreeOuterFrame.cpp

@@ -0,0 +1,72 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "License"); you may not use this file except in
+ * compliance with the License.  You may obtain a copy of the License at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * The Original Code is Mozilla Communicator client code.
+ *
+ * The Initial Developer of the Original Code is Netscape Communications
+ * Corporation.  Portions created by Netscape are Copyright (C) 1998
+ * Netscape Communications Corporation.  All Rights Reserved.
+ */
+
+#include "nsCOMPtr.h"
+#include "nsTreeOuterFrame.h"
+#include "nsIStyleContext.h"
+#include "nsIContent.h"
+#include "nsCSSRendering.h"
+#include "nsTreeCellFrame.h"
+#include "nsCellMap.h"
+#include "nsIDOMXULTreeElement.h"
+#include "nsINameSpaceManager.h"
+
+//
+// NS_NewTreeOuterFrame
+//
+// Creates a new tree frame
+//
+nsresult
+NS_NewTreeOuterFrame (nsIFrame** aNewFrame)
+{
+  NS_PRECONDITION(aNewFrame, "null OUT ptr");
+  if (nsnull == aNewFrame) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  nsTreeOuterFrame* it = new nsTreeOuterFrame;
+  if (!it)
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  *aNewFrame = it;
+  return NS_OK;
+  
+} // NS_NewTreeOuterFrame
+
+
+// Constructor
+nsTreeOuterFrame::nsTreeOuterFrame()
+:nsTableOuterFrame() { }
+
+// Destructor
+nsTreeOuterFrame::~nsTreeOuterFrame()
+{
+}
+
+NS_IMETHODIMP 
+nsTreeOuterFrame::HandleEvent(nsIPresContext& aPresContext, 
+                             nsGUIEvent*     aEvent,
+                             nsEventStatus&  aEventStatus)
+{
+  aEventStatus = nsEventStatus_eConsumeDoDefault;
+  if (aEvent->message == NS_KEY_DOWN) {
+    printf("YES!\n");
+  }
+  return NS_OK;
+}
+

layout/xul/base/src/nsTreeOuterFrame.h

@@ -0,0 +1,37 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "License"); you may not use this file except in
+ * compliance with the License.  You may obtain a copy of the License at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * The Original Code is Mozilla Communicator client code.
+ *
+ * The Initial Developer of the Original Code is Netscape Communications
+ * Corporation.  Portions created by Netscape are Copyright (C) 1998
+ * Netscape Communications Corporation.  All Rights Reserved.
+ */
+
+#include "nsTableOuterFrame.h"
+
+class nsTreeOuterFrame : public nsTableOuterFrame
+{
+public:
+  friend nsresult NS_NewTreeOuterFrame(nsIFrame** aNewFrame);
+
+  NS_IMETHOD HandleEvent(nsIPresContext& aPresContext, 
+                             nsGUIEvent*     aEvent,
+                             nsEventStatus&  aEventStatus);
+
+protected:
+  nsTreeOuterFrame();
+  virtual ~nsTreeOuterFrame();
+
+protected: // Data Members
+  
+}; // class nsTreeOuterFrame