Table rows/cols and groups don't paint their backgrounds, so CanPaintBackground must return false. b=236053 r+sr=roc

layout/html/table/src/nsTableColFrame.h

@@ -116,6 +116,9 @@ public:
                    nsFramePaintLayer    aWhichLayer,
                    PRUint32             aFlags = 0);
 
+  // column groups don't paint their own background -- the cells do
+  virtual PRBool CanPaintBackground() { return PR_FALSE; }
+
   NS_IMETHOD GetFrameForPoint(nsIPresContext* aPresContext,
                               const nsPoint& aPoint, 
                               nsFramePaintLayer aWhichLayer,

layout/html/table/src/nsTableColGroupFrame.h

@@ -117,6 +117,9 @@ public:
                    nsFramePaintLayer    aWhichLayer,
                    PRUint32             aFlags = 0);
 
+  // column groups don't paint their own background -- the cells do
+  virtual PRBool CanPaintBackground() { return PR_FALSE; }
+
   NS_IMETHOD GetFrameForPoint(nsIPresContext* aPresContext,
                               const nsPoint& aPoint, 
                               nsFramePaintLayer aWhichLayer,

layout/html/table/src/nsTableRowFrame.h

@@ -103,6 +103,9 @@ public:
                    nsFramePaintLayer    aWhichLayer,
                    PRUint32             aFlags = 0);
 
+  // rows don't paint their own background -- the cells do
+  virtual PRBool CanPaintBackground() { return PR_FALSE; }
+
   NS_IMETHOD GetFrameForPoint(nsIPresContext*   aPresContext,
                               const nsPoint&    aPoint, 
                               nsFramePaintLayer aWhichLayer,

layout/html/table/src/nsTableRowGroupFrame.h

@@ -143,6 +143,9 @@ public:
                    nsFramePaintLayer    aWhichLayer,
                    PRUint32             aFlags = 0);
 
+  // row groups don't paint their own background -- the cells do
+  virtual PRBool CanPaintBackground() { return PR_FALSE; }
+
   /** ask all children to paint themselves, without clipping (for cells with rowspan>1)
     * @see nsIFrame::Paint 
     */

layout/tables/nsTableColFrame.h

@@ -116,6 +116,9 @@ public:
                    nsFramePaintLayer    aWhichLayer,
                    PRUint32             aFlags = 0);
 
+  // column groups don't paint their own background -- the cells do
+  virtual PRBool CanPaintBackground() { return PR_FALSE; }
+
   NS_IMETHOD GetFrameForPoint(nsIPresContext* aPresContext,
                               const nsPoint& aPoint, 
                               nsFramePaintLayer aWhichLayer,

layout/tables/nsTableColGroupFrame.h

@@ -117,6 +117,9 @@ public:
                    nsFramePaintLayer    aWhichLayer,
                    PRUint32             aFlags = 0);
 
+  // column groups don't paint their own background -- the cells do
+  virtual PRBool CanPaintBackground() { return PR_FALSE; }
+
   NS_IMETHOD GetFrameForPoint(nsIPresContext* aPresContext,
                               const nsPoint& aPoint, 
                               nsFramePaintLayer aWhichLayer,

layout/tables/nsTableRowFrame.h

@@ -103,6 +103,9 @@ public:
                    nsFramePaintLayer    aWhichLayer,
                    PRUint32             aFlags = 0);
 
+  // rows don't paint their own background -- the cells do
+  virtual PRBool CanPaintBackground() { return PR_FALSE; }
+
   NS_IMETHOD GetFrameForPoint(nsIPresContext*   aPresContext,
                               const nsPoint&    aPoint, 
                               nsFramePaintLayer aWhichLayer,

layout/tables/nsTableRowGroupFrame.h

@@ -143,6 +143,9 @@ public:
                    nsFramePaintLayer    aWhichLayer,
                    PRUint32             aFlags = 0);
 
+  // row groups don't paint their own background -- the cells do
+  virtual PRBool CanPaintBackground() { return PR_FALSE; }
+
   /** ask all children to paint themselves, without clipping (for cells with rowspan>1)
     * @see nsIFrame::Paint 
     */