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

third_party/WebKit/Source/core/layout/LayoutTableBoxComponent.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/layout/LayoutTableBoxComponent.h"
 
+#include "core/layout/LayoutTable.h"
 #include "core/style/ComputedStyle.h"
 
 namespace blink {
 
 void LayoutTableBoxComponent::styleDidChange(StyleDifference diff, const ComputedStyle* oldStyle)
 {
     LayoutBox::styleDidChange(diff, oldStyle);
 
     if (parent() && oldStyle) {
         if (resolveColor(*oldStyle, CSSPropertyBackgroundColor) != resolveColor(CSSPropertyBackgroundColor)
             || oldStyle->backgroundLayers() != styleRef().backgroundLayers())
             m_backgroundChangedSinceLastPaintInvalidation = true;
     }
 }
 
 void LayoutTableBoxComponent::imageChanged(WrappedImagePtr, const IntRect*)
 {
     setShouldDoFullPaintInvalidation();
     m_backgroundChangedSinceLastPaintInvalidation = true;
 }
 
+/*static*/ bool LayoutTableBoxComponent::doCellsHaveDirtyWidth(const LayoutObject& tablePart, const LayoutTable& table, const StyleDifference& diff, const ComputedStyle& oldStyle)

[eae, 2016/07/18 16:21:53]

Uncomment or remove static modifier.

[dgrogan, 2016/07/18 17:24:27]

I removed it... it's only allowed to be specified in the class definition so
uncommenting isn't viable.

+{
+    // ComputedStyle::diffNeedsFullLayoutAndPaintInvalidation sets needsFullLayout when border sizes
+    // change: checking diff.needsFullLayout() is an optimization, not required for correctness.
+    // TODO(dgrogan): Remove tablePart.needsLayout()? Perhaps it was an old optimization but now it
+    // seems that diff.needsFullLayout() implies tablePart.needsLayout().
+    return diff.needsFullLayout() && tablePart.needsLayout() && table.collapseBorders() && !oldStyle.border().sizeEquals(tablePart.style()->border());
+}
+
 } // namespace blink