Optimize collapsed border calculation (step 2)

third_party/WebKit/Source/core/layout/LayoutTableCol.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, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 37 matching lines @@
 
   LayoutTableBoxComponent::StyleDidChange(diff, old_style);
 
   if (!old_style)
     return;
 
   LayoutTable* table = this->Table();
   if (!table)
     return;
 
-  LayoutTableBoxComponent::InvalidateCollapsedBordersOnStyleChange(
-      *this, *table, diff, *old_style);
+  if (LayoutTableBoxComponent::NeedsInvalidateCollapsedBordersOnStyleChange(
+          *this, *table, diff, *old_style))
+    table->SetNeedsInvalidateCollapsedBordersForAllCells();
 
   if ((old_style->LogicalWidth() != Style()->LogicalWidth()) ||
       LayoutTableBoxComponent::DoCellsHaveDirtyWidth(*this, *table, diff,
                                                      *old_style)) {
     // TODO(dgrogan): Optimization opportunities:
     // (1) Only mark cells which are affected by this col, not every cell in the
     //     table.
     // (2) If only the col width changes and its border width doesn't, do the
     //     cells need to be marked as needing layout or just given dirty
     //     widths?
@@ skipping 120 matching lines @@
 const BorderValue& LayoutTableCol::BorderAdjoiningCellAfter(
     const LayoutTableCell* cell) const {
   DCHECK_EQ(Table()
                 ->ColElementAtAbsoluteColumn(cell->AbsoluteColumnIndex() - 1)
                 .InnermostColOrColGroup(),
             this);
   return Style()->BorderEnd();
 }
 
 }  // namespace blink