Have RenderBlockFlow sub-classes' methods call their super-class method properly.

Source/core/rendering/RenderFieldset.cpp

Index: Source/core/rendering/RenderFieldset.cpp
diff --git a/Source/core/rendering/RenderFieldset.cpp b/Source/core/rendering/RenderFieldset.cpp
index b3962cf6f0a9e1d4ef5f1daa1078bee95c80f530..2537a9d45d712c6b71f7f9c059f47de17fe81a8f 100644
--- a/Source/core/rendering/RenderFieldset.cpp
+++ b/Source/core/rendering/RenderFieldset.cpp
@@ -43,7 +43,7 @@ RenderFieldset::RenderFieldset(Element* element)
 
 void RenderFieldset::computePreferredLogicalWidths()
 {
-    RenderBlock::computePreferredLogicalWidths();
+    RenderBlockFlow::computePreferredLogicalWidths();
     if (RenderBox* legend = findLegend()) {
         int legendMinWidth = legend->minPreferredLogicalWidth();
 
@@ -143,7 +143,7 @@ void RenderFieldset::paintBoxDecorations(PaintInfo& paintInfo, const LayoutPoint
     LayoutRect paintRect(paintOffset, size());
     RenderBox* legend = findLegend();
     if (!legend)
-        return RenderBlock::paintBoxDecorations(paintInfo, paintOffset);
+        return RenderBlockFlow::paintBoxDecorations(paintInfo, paintOffset);
 
     // FIXME: We need to work with "rl" and "bt" block flow directions.  In those
     // cases the legend is embedded in the right and bottom borders respectively.
@@ -194,7 +194,7 @@ void RenderFieldset::paintMask(PaintInfo& paintInfo, const LayoutPoint& paintOff
     LayoutRect paintRect = LayoutRect(paintOffset, size());
     RenderBox* legend = findLegend();
     if (!legend)
-        return RenderBlock::paintMask(paintInfo, paintOffset);
+        return RenderBlockFlow::paintMask(paintInfo, paintOffset);
 
     // FIXME: We need to work with "rl" and "bt" block flow directions.  In those
     // cases the legend is embedded in the right and bottom borders respectively.