(WIP) Paint invalidation for slimming paint v2

Source/core/layout/LayoutTable.cpp

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1379 matching lines @@
 }
 
 PaintInvalidationReason LayoutTable::invalidatePaintIfNeeded(PaintInvalidationState& paintInvalidationState, const LayoutBoxModelObject& paintInvalidationContainer)
 {
     // Information of collapsed borders doesn't affect layout and are for painting only.
     // Do it now instead of during painting to invalidate table cells if needed.
     recalcCollapsedBordersIfNeeded();
     return LayoutBlock::invalidatePaintIfNeeded(paintInvalidationState, paintInvalidationContainer);
 }
 
+PaintInvalidationReason LayoutTable::invalidatePaintIfNeededForSlimmingPaintV2(const LayoutPoint& newPaintOffset)
+{
+    // Information of collapsed borders doesn't affect layout and are for painting only.
+    // Do it now instead of during painting to invalidate table cells if needed.
+    recalcCollapsedBordersIfNeeded();
+    return LayoutBlock::invalidatePaintIfNeededForSlimmingPaintV2(newPaintOffset);
+}
+
 void LayoutTable::invalidatePaintOfSubtreesIfNeeded(PaintInvalidationState& childPaintInvalidationState)
 {
     if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
         // Table cells paint background from the containing column group, column, section and row.
         // If background of any of them changed, we need to invalidate all affected cells.
         // Here use shouldDoFullPaintInvalidation() as a broader condition of background change.
         for (LayoutObject* section = firstChild(); section; section = section->nextSibling()) {
             if (!section->isTableSection())
                 continue;
             for (LayoutTableRow* row = toLayoutTableSection(section)->firstRow(); row; row = row->nextRow()) {
                 for (LayoutTableCell* cell = row->firstCell(); cell; cell = cell->nextCell()) {
                     LayoutTableCol* column = colElement(cell->col());
                     LayoutTableCol* columnGroup = column ? column->enclosingColumnGroup() : 0;
                     if ((columnGroup && columnGroup->shouldDoFullPaintInvalidation())
                         || (column && column->shouldDoFullPaintInvalidation())
                         || section->shouldDoFullPaintInvalidation()
                         || row->shouldDoFullPaintInvalidation())
                         cell->invalidateDisplayItemClient(*cell);
                 }
             }
         }
     }
 
     LayoutBlock::invalidatePaintOfSubtreesIfNeeded(childPaintInvalidationState);
 }
 
 }