diff -r 000000000000 -r 6474c204b198 layout/xul/nsListItemFrame.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/xul/nsListItemFrame.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,68 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsListItemFrame.h"
+
+#include "nsCOMPtr.h"
+#include "nsNameSpaceManager.h"
+#include "nsGkAtoms.h"
+#include "nsDisplayList.h"
+#include "nsBoxLayout.h"
+#include <algorithm>
+
+nsListItemFrame::nsListItemFrame(nsIPresShell* aPresShell,
+                                 nsStyleContext* aContext,
+                                 bool aIsRoot,
+                                 nsBoxLayout* aLayoutManager)
+  : nsGridRowLeafFrame(aPresShell, aContext, aIsRoot, aLayoutManager) 
+{
+}
+
+nsListItemFrame::~nsListItemFrame()
+{
+}
+
+nsSize
+nsListItemFrame::GetPrefSize(nsBoxLayoutState& aState)
+{
+  nsSize size = nsBoxFrame::GetPrefSize(aState);  
+  DISPLAY_PREF_SIZE(this, size);
+
+  // guarantee that our preferred height doesn't exceed the standard
+  // listbox row height
+  size.height = std::max(mRect.height, size.height);
+  return size;
+}
+
+void
+nsListItemFrame::BuildDisplayListForChildren(nsDisplayListBuilder*   aBuilder,
+                                             const nsRect&           aDirtyRect,
+                                             const nsDisplayListSet& aLists)
+{
+  if (aBuilder->IsForEventDelivery()) {
+    if (!mContent->AttrValueIs(kNameSpaceID_None, nsGkAtoms::allowevents,
+                               nsGkAtoms::_true, eCaseMatters))
+      return;
+  }
+  
+  nsGridRowLeafFrame::BuildDisplayListForChildren(aBuilder, aDirtyRect, aLists);
+}
+
+// Creation Routine ///////////////////////////////////////////////////////////////////////
+
+already_AddRefed<nsBoxLayout> NS_NewGridRowLeafLayout();
+
+nsIFrame*
+NS_NewListItemFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
+{
+  nsCOMPtr<nsBoxLayout> layout = NS_NewGridRowLeafLayout();
+  if (!layout) {
+    return nullptr;
+  }
+  
+  return new (aPresShell) nsListItemFrame(aPresShell, aContext, false, layout);
+}
+
+NS_IMPL_FRAMEARENA_HELPERS(nsListItemFrame)