[css-tables] Clean up code that detects significant border changes

third_party/WebKit/Source/core/layout/LayoutTableSection.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, 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 101 matching lines @@
     // init LayoutObject attributes
     setInline(false); // our object is not Inline
 }
 
 LayoutTableSection::~LayoutTableSection()
 {
 }
 
 void LayoutTableSection::styleDidChange(StyleDifference diff, const ComputedStyle* oldStyle)
 {
+    DCHECK(style()->display() == TABLE_FOOTER_GROUP || style()->display() == TABLE_ROW_GROUP || style()->display() == TABLE_HEADER_GROUP);
+
     LayoutTableBoxComponent::styleDidChange(diff, oldStyle);
     propagateStyleToAnonymousChildren();
 
-    // If border was changed, notify table.
+    if (!oldStyle)
+        return;
+
     LayoutTable* table = this->table();
-    if (table && !table->selfNeedsLayout() && !table->normalChildNeedsLayout() && oldStyle && oldStyle->border() != style()->border())
+    if (!table)
+        return;
+
+    if (!table->selfNeedsLayout() && !table->normalChildNeedsLayout() && oldStyle->border() != style()->border())
         table->invalidateCollapsedBorders();
 
-    if (table && oldStyle && diff.needsFullLayout() && needsLayout() && table->collapseBorders() && oldStyle->border() != style()->border()) {
+    if (LayoutTableBoxComponent::doCellsHaveDirtyWidth(*this, *table, diff, *oldStyle))
         markAllCellsWidthsDirtyAndOrNeedsLayout(MarkDirtyAndNeedsLayout);
-    }
 }
 
 void LayoutTableSection::willBeRemovedFromTree()
 {
     LayoutTableBoxComponent::willBeRemovedFromTree();
 
     // Preventively invalidate our cells as we may be re-inserted into
     // a new table which would require us to rebuild our structure.
     setNeedsCellRecalc();
 }
@@ skipping 1582 matching lines @@
     // Repeating table headers are painted once per fragmentation page/column. This does not go through the regular fragmentation machinery,
     // so we need special code to expand the invalidation rect to contain all positions of the header in all columns.
     // Note that this is in flow thread coordinates, not visual coordinates. The enclosing LayoutFlowThread will convert to visual coordinates.
     if (table()->header() == this && hasRepeatingHeaderGroup())
         rect.setHeight(table()->logicalHeight());
     return LayoutTableBoxComponent::mapToVisualRectInAncestorSpace(ancestor, rect, flags);
 }
 
 
 } // namespace blink