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

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 27 matching lines @@
     : LayoutTableBoxComponent(element)
     , m_span(1)
 {
     // init LayoutObject attributes
     setInline(true); // our object is not Inline
     updateFromElement();
 }
 
 void LayoutTableCol::styleDidChange(StyleDifference diff, const ComputedStyle* oldStyle)
 {
+    DCHECK(style()->display() == TABLE_COLUMN || style()->display() == TABLE_COLUMN_GROUP);
+
     LayoutTableBoxComponent::styleDidChange(diff, oldStyle);
 
-    if (LayoutTable* table = this->table()) {
-        if (!oldStyle)
-            return;
+    if (!oldStyle)
+        return;
 
-        // TODO(dgrogan): Is the "else" necessary for correctness or just a brittle optimization? The optimization would be:
-        // if the first branch is taken then the next one can't be, so don't even check its condition.
-        if (!table->selfNeedsLayout() && !table->normalChildNeedsLayout() && oldStyle->border() != style()->border()) {
-            // If border was changed, notify table.
-            table->invalidateCollapsedBorders();
-        } else if ((oldStyle->logicalWidth() != style()->logicalWidth()) || (diff.needsFullLayout() && needsLayout() && table->collapseBorders() && oldStyle->border().sizeEquals(style()->border()))) {
-            // TODO(dgrogan): Move second clause above to LayoutTableBoxComponent for re-use.
-            // 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?
-            for (LayoutObject* child = table->children()->firstChild(); child; child = child->nextSibling()) {
-                if (!child->isTableSection())
-                    continue;
-                LayoutTableSection* section = toLayoutTableSection(child);
-                section->markAllCellsWidthsDirtyAndOrNeedsLayout(LayoutTableSection::MarkDirtyAndNeedsLayout);
-            }
+    LayoutTable* table = this->table();
+    if (!table)
+        return;
+
+    // TODO(dgrogan): Is the "else" necessary for correctness or just a brittle optimization? The optimization would be:
+    // if the first branch is taken then the next one can't be, so don't even check its condition.
+    if (!table->selfNeedsLayout() && !table->normalChildNeedsLayout() && oldStyle->border() != style()->border()) {
+        table->invalidateCollapsedBorders();
+    } else if ((oldStyle->logicalWidth() != style()->logicalWidth()) || LayoutTableBoxComponent::doCellsHaveDirtyWidth(*this, *table, diff, *oldStyle)) {
+        // 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?
+        for (LayoutObject* child = table->children()->firstChild(); child; child = child->nextSibling()) {
+            if (!child->isTableSection())
+                continue;
+            LayoutTableSection* section = toLayoutTableSection(child);
+            section->markAllCellsWidthsDirtyAndOrNeedsLayout(LayoutTableSection::MarkDirtyAndNeedsLayout);
         }
     }
 }
 
 void LayoutTableCol::updateFromElement()
 {
     unsigned oldSpan = m_span;
     Node* n = node();
     if (isHTMLTableColElement(n)) {
         HTMLTableColElement& tc = toHTMLTableColElement(*n);
@@ skipping 108 matching lines @@
     return style()->borderStart();
 }
 
 const BorderValue& LayoutTableCol::borderAdjoiningCellAfter(const LayoutTableCell* cell) const
 {
     ASSERT_UNUSED(cell, table()->colElementAtAbsoluteColumn(cell->absoluteColumnIndex() - 1).innermostColOrColGroup() == this);
     return style()->borderEnd();
 }
 
 } // namespace blink