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

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

Index: third_party/WebKit/Source/core/layout/LayoutTableCol.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutTableCol.cpp b/third_party/WebKit/Source/core/layout/LayoutTableCol.cpp
index c5f256e701f39a32fc329c920355357966d9f7b2..d96fa37ddd097add46ebc219ae167a4e995248bb 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableCol.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutTableCol.cpp
@@ -45,29 +45,31 @@ LayoutTableCol::LayoutTableCol(Element* element)
 
 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;
-
-        // 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);
-            }
+    if (!oldStyle)
+        return;
+
+    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);
         }
     }
 }