diff -r 000000000000 -r 6474c204b198 layout/tables/BasicTableLayoutStrategy.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/tables/BasicTableLayoutStrategy.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,81 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+// vim:cindent:ts=4:et:sw=4:
+/* 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/. */
+
+/*
+ * Web-compatible algorithms that determine column and table widths,
+ * used for CSS2's 'table-layout: auto'.
+ */
+
+#ifndef BasicTableLayoutStrategy_h_
+#define BasicTableLayoutStrategy_h_
+
+#include "mozilla/Attributes.h"
+#include "nsITableLayoutStrategy.h"
+
+class nsTableFrame;
+
+class BasicTableLayoutStrategy : public nsITableLayoutStrategy
+{
+public:
+    BasicTableLayoutStrategy(nsTableFrame *aTableFrame);
+    virtual ~BasicTableLayoutStrategy();
+
+    // nsITableLayoutStrategy implementation
+    virtual nscoord GetMinWidth(nsRenderingContext* aRenderingContext) MOZ_OVERRIDE;
+    virtual nscoord GetPrefWidth(nsRenderingContext* aRenderingContext,
+                                 bool aComputingSize) MOZ_OVERRIDE;
+    virtual void MarkIntrinsicWidthsDirty() MOZ_OVERRIDE;
+    virtual void ComputeColumnWidths(const nsHTMLReflowState& aReflowState) MOZ_OVERRIDE;
+
+private:
+    // NOTE: Using prefix "BTLS" to avoid overlapping names with 
+    // the values of nsLayoutUtils::IntrinsicWidthType
+    enum BtlsWidthType { BTLS_MIN_WIDTH, 
+                         BTLS_PREF_WIDTH, 
+                         BTLS_FINAL_WIDTH };
+
+    // Compute intrinsic width member variables on the columns.
+    void ComputeColumnIntrinsicWidths(nsRenderingContext* aRenderingContext);
+
+    // Distribute a colspanning cell's percent width (if any) to its columns.
+    void DistributePctWidthToColumns(float aSpanPrefPct,
+                                     int32_t aFirstCol,
+                                     int32_t aColCount);
+
+    // Distribute a width of some BltsWidthType type to a set of columns.
+    //  aWidth: The amount of width to be distributed
+    //  aFirstCol: The index (in the table) of the first column to be
+    //             considered for receiving width
+    //  aColCount: The number of consecutive columns (starting with aFirstCol)
+    //             to be considered for receiving width
+    //  aWidthType: The type of width being distributed.  (BTLS_MIN_WIDTH and
+    //              BTLS_PREF_WIDTH are intended to be used for dividing up
+    //              colspan's min & pref width.  BTLS_FINAL_WIDTH is intended
+    //              to be used for distributing the table's final width across
+    //              all its columns)
+    //  aSpanHasSpecifiedWidth: Should be true iff:
+    //                           - We're distributing a colspanning cell's
+    //                             pref or min width to its columns
+    //                           - The colspanning cell has a specified width.
+    void DistributeWidthToColumns(nscoord aWidth, 
+                                  int32_t aFirstCol, 
+                                  int32_t aColCount,
+                                  BtlsWidthType aWidthType,
+                                  bool aSpanHasSpecifiedWidth);
+ 
+
+    // Compute the min and pref widths of the table from the width
+    // variables on the columns.
+    void ComputeIntrinsicWidths(nsRenderingContext* aRenderingContext);
+
+    nsTableFrame *mTableFrame;
+    nscoord mMinWidth;
+    nscoord mPrefWidth;
+    nscoord mPrefWidthPctExpand;
+    nscoord mLastCalcWidth;
+};
+
+#endif /* !defined(BasicTableLayoutStrategy_h_) */