Improve positioned/percentHeight descendant/container tracking

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 101 matching lines @@
 
     return NoPaintLayer;
 }
 
 void LayoutBox::willBeDestroyed()
 {
     clearOverrideSize();
     clearContainingBlockOverrideSize();
     clearExtraInlineAndBlockOffests();
 
-    LayoutBlock::removePercentHeightDescendantIfNeeded(this);
+    removeFromPositionedContainer();
+    removeFromPercentHeightContainer();
 
     ShapeOutsideInfo::removeInfo(*this);
 
     LayoutBoxModelObject::willBeDestroyed();
 }
 
 void LayoutBox::removeFloatingOrPositionedChildFromBlockLists()
 {
     ASSERT(isFloatingOrOutOfFlowPositioned());
 
@@ skipping 10 matching lines @@
             }
         }
 
         if (parentBlockFlow) {
             parentBlockFlow->markSiblingsWithFloatsForLayout(this);
             parentBlockFlow->markAllDescendantsWithFloatsForLayout(this, false);
         }
     }
 
     if (isOutOfFlowPositioned())
-        LayoutBlock::removePositionedObject(this);
+        removeFromPositionedContainer();
 }
 
 void LayoutBox::styleWillChange(StyleDifference diff, const ComputedStyle& newStyle)
 {
     const ComputedStyle* oldStyle = style();
     if (oldStyle) {
         LayoutFlowThread* flowThread = flowThreadContainingBlock();
         if (flowThread && flowThread != this)
             flowThread->flowThreadDescendantStyleWillChange(this, diff, newStyle);
 
@@ skipping 37 matching lines @@
 {
     // Horizontal writing mode definition is updated in LayoutBoxModelObject::updateFromStyle,
     // (as part of the LayoutBoxModelObject::styleDidChange call below). So, we can safely cache the horizontal
     // writing mode value before style change here.
     bool oldHorizontalWritingMode = isHorizontalWritingMode();
 
     LayoutBoxModelObject::styleDidChange(diff, oldStyle);
 
     const ComputedStyle& newStyle = styleRef();
     if (needsLayout() && oldStyle)
-        LayoutBlock::removePercentHeightDescendantIfNeeded(this);
+        removeFromPercentHeightContainer();
 
-    if (LayoutBlock::hasPercentHeightContainerMap() && slowFirstChild()
-        && oldHorizontalWritingMode != isHorizontalWritingMode())
-        LayoutBlock::clearPercentHeightDescendantsFrom(this);
+    if (oldHorizontalWritingMode != isHorizontalWritingMode())
+        clearPercentHeightDescendants();
 
     // If our zoom factor changes and we have a defined scrollLeft/Top, we need to adjust that value into the
     // new zoomed coordinate space.
     if (hasOverflowClip() && oldStyle && oldStyle->effectiveZoom() != newStyle.effectiveZoom() && layer()) {
         if (int left = layer()->scrollableArea()->scrollXOffset()) {
             left = (left / oldStyle->effectiveZoom()) * newStyle.effectiveZoom();
             layer()->scrollableArea()->scrollToXOffset(left);
         }
         if (int top = layer()->scrollableArea()->scrollYOffset()) {
             top = (top / oldStyle->effectiveZoom()) * newStyle.effectiveZoom();
@@ skipping 4662 matching lines @@
     return ShapeOutsideInfo::isEnabledFor(*this) ? ShapeOutsideInfo::info(*this) : nullptr;
 }
 
 void LayoutBox::clearPreviousPaintInvalidationRects()
 {
     LayoutBoxModelObject::clearPreviousPaintInvalidationRects();
     if (PaintLayerScrollableArea* scrollableArea = this->scrollableArea())
         scrollableArea->clearPreviousPaintInvalidationRects();
 }
 
+void LayoutBox::setPositionedContainer(LayoutBlock* container)
+{
+    ASSERT(!container || !positionedContainer());
+    if (!container && !m_rareData)
+        return;
+    ensureRareData().m_positionedContainer = container;
+}
+
+void LayoutBox::removeFromPositionedContainer()
+{
+    if (!positionedContainer())
+        return;
+
+    ASSERT(positionedContainer()->positionedObjects()->contains(this));
+    positionedContainer()->removePositionedObject(this);
+    // The above call should call this object's setPositionedContainer(nullptr).
+    ASSERT(!positionedContainer());
+}
+
+void LayoutBox::setPercentHeightContainer(LayoutBlock* container)
+{
+    ASSERT(!container || !percentHeightContainer());
+    if (!container && !m_rareData)
+        return;
+    ensureRareData().m_percentHeightContainer = container;
+}
+
+void LayoutBox::removeFromPercentHeightContainer()
+{
+    if (!percentHeightContainer())
+        return;
+
+    ASSERT(percentHeightContainer()->hasPercentHeightDescendant(this));
+    percentHeightContainer()->removePercentHeightDescendant(this);
+    // The above call should call this object's setPercentHeightContainer(nullptr).
+    ASSERT(!percentHeightContainer());
+}
+
+void LayoutBox::clearPercentHeightDescendants()
+{
+    for (LayoutObject* curr = slowFirstChild(); curr; curr = curr->nextInPreOrder(this)) {
+        if (curr->isBox())
+            toLayoutBox(curr)->removeFromPercentHeightContainer();
+    }
+}
+
 } // namespace blink