diff -r 000000000000 -r 6474c204b198 layout/xul/grid/nsGridCell.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/xul/grid/nsGridCell.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,127 @@
+/* -*- 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/. */
+
+//
+// Eric Vaughan
+// Netscape Communications
+//
+// See documentation in associated header file
+//
+
+#include "nsGridCell.h"
+#include "nsFrame.h"
+#include "nsBox.h"
+#include "nsGridLayout2.h"
+
+
+nsGridCell::nsGridCell():mBoxInColumn(nullptr),mBoxInRow(nullptr)
+{
+    MOZ_COUNT_CTOR(nsGridCell);
+}                                               
+        
+nsGridCell::~nsGridCell()
+{
+    MOZ_COUNT_DTOR(nsGridCell);
+}
+
+nsSize
+nsGridCell::GetPrefSize(nsBoxLayoutState& aState)
+{
+  nsSize sum(0,0);
+
+  // take our 2 children and add them up.
+  // we are as wide as the widest child plus its left offset
+  // we are tall as the tallest child plus its top offset
+
+  if (mBoxInColumn) {
+    nsSize pref = mBoxInColumn->GetPrefSize(aState);
+
+    nsBox::AddMargin(mBoxInColumn, pref);
+    nsGridLayout2::AddOffset(aState, mBoxInColumn, pref);
+
+    nsBoxLayout::AddLargestSize(sum, pref);
+  }
+
+  if (mBoxInRow) {
+    nsSize pref = mBoxInRow->GetPrefSize(aState);
+
+    nsBox::AddMargin(mBoxInRow, pref);
+    nsGridLayout2::AddOffset(aState, mBoxInRow, pref);
+
+    nsBoxLayout::AddLargestSize(sum, pref);
+  }
+
+  return sum;
+}
+
+nsSize
+nsGridCell::GetMinSize(nsBoxLayoutState& aState)
+{
+  nsSize sum(0, 0);
+
+  // take our 2 children and add them up.
+  // we are as wide as the widest child plus its left offset
+  // we are tall as the tallest child plus its top offset
+
+  if (mBoxInColumn) {
+    nsSize min = mBoxInColumn->GetMinSize(aState);
+
+    nsBox::AddMargin(mBoxInColumn, min);
+    nsGridLayout2::AddOffset(aState, mBoxInColumn, min);
+
+    nsBoxLayout::AddLargestSize(sum, min);
+  }
+
+  if (mBoxInRow) {
+    nsSize min = mBoxInRow->GetMinSize(aState);
+
+    nsBox::AddMargin(mBoxInRow, min);
+    nsGridLayout2::AddOffset(aState, mBoxInRow, min);
+
+    nsBoxLayout::AddLargestSize(sum, min);
+  }
+
+  return sum;
+}
+
+nsSize
+nsGridCell::GetMaxSize(nsBoxLayoutState& aState)
+{
+  nsSize sum(NS_INTRINSICSIZE, NS_INTRINSICSIZE);
+
+  // take our 2 children and add them up.
+  // we are as wide as the smallest child plus its left offset
+  // we are tall as the shortest child plus its top offset
+
+  if (mBoxInColumn) {
+    nsSize max = mBoxInColumn->GetMaxSize(aState);
+ 
+    nsBox::AddMargin(mBoxInColumn, max);
+    nsGridLayout2::AddOffset(aState, mBoxInColumn, max);
+
+    nsBoxLayout::AddSmallestSize(sum, max);
+  }
+
+  if (mBoxInRow) {
+    nsSize max = mBoxInRow->GetMaxSize(aState);
+
+    nsBox::AddMargin(mBoxInRow, max);
+    nsGridLayout2::AddOffset(aState, mBoxInRow, max);
+
+    nsBoxLayout::AddSmallestSize(sum, max);
+  }
+
+  return sum;
+}
+
+
+bool
+nsGridCell::IsCollapsed()
+{
+  return ((mBoxInColumn && mBoxInColumn->IsCollapsed()) ||
+          (mBoxInRow && mBoxInRow->IsCollapsed()));
+}
+
+