Change LayoutState to be stack-allocated

Source/core/rendering/RenderBox.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 303 matching lines @@
 void RenderBox::layout()
 {
     ASSERT(needsLayout());
 
     RenderObject* child = slowFirstChild();
     if (!child) {
         clearNeedsLayout();
         return;
     }
 
-    LayoutStateMaintainer statePusher(*this, locationOffset());
+    LayoutState state(*this, locationOffset());
     while (child) {
         child->layoutIfNeeded();
         ASSERT(!child->needsLayout());
         child = child->nextSibling();
     }
     invalidateBackgroundObscurationStatus();
     clearNeedsLayout();
 }
 
 // More IE extensions.  clientWidth and clientHeight represent the interior of an object
@@ skipping 1246 matching lines @@
 
     const LayoutRect oldPaintInvalidationRect = previousPaintInvalidationRect();
     const LayoutPoint oldPositionFromPaintInvalidationContainer = previousPositionFromPaintInvalidationContainer();
     setPreviousPaintInvalidationRect(boundsRectForPaintInvalidation(&newPaintInvalidationContainer));
     setPreviousPositionFromPaintInvalidationContainer(positionFromPaintInvalidationContainer(&newPaintInvalidationContainer));
 
     // If we are set to do a full paint invalidation that means the RenderView will be
     // issue paint invalidations. We can then skip issuing of paint invalidations for the child
     // renderers as they'll be covered by the RenderView.
     if (view()->doingFullRepaint()) {
-        LayoutStateMaintainer statePusher(*this, isTableRow() ? LayoutSize() : locationOffset());
+        LayoutState state(*this, isTableRow() ? LayoutSize() : locationOffset());
         RenderObject::invalidateTreeAfterLayout(newPaintInvalidationContainer);
         return;
     }
 
     if ((onlyNeededPositionedMovementLayout() && compositingState() != PaintsIntoOwnBacking)
         || (shouldDoFullPaintInvalidationIfSelfPaintingLayer()
             && hasLayer()
             && layer()->isSelfPaintingLayer())) {
         setShouldDoFullPaintInvalidationAfterLayout(true);
     }
@@ skipping 19 matching lines @@
     }
 
     // FIXME: LayoutState should be enabled for other paint invalidation containers than the RenderView. crbug.com/363834
     if (establishesNewPaintInvalidationContainer && !isRenderView()) {
         ForceHorriblySlowRectMapping slowRectMapping(*this);
         RenderObject::invalidateTreeAfterLayout(newPaintInvalidationContainer);
     } else {
         // FIXME: This concept of a tree walking state for fast lookups should be generalized away from
         // just layout.
         // FIXME: Table rows shouldn't be special-cased.
-        LayoutStateMaintainer statePusher(*this, isTableRow() ? LayoutSize() : locationOffset());
+        LayoutState state(*this, isTableRow() ? LayoutSize() : locationOffset());
         RenderObject::invalidateTreeAfterLayout(newPaintInvalidationContainer);
     }
 }
 
 bool RenderBox::pushContentsClip(PaintInfo& paintInfo, const LayoutPoint& accumulatedOffset, ContentsClipBehavior contentsClipBehavior)
 {
     if (paintInfo.phase == PaintPhaseBlockBackground || paintInfo.phase == PaintPhaseSelfOutline || paintInfo.phase == PaintPhaseMask)
         return false;
 
     bool isControlClip = hasControlClip();
@@ skipping 168 matching lines @@
     // Use the content box logical height as specified by the style.
     return cb->adjustContentBoxLogicalHeightForBoxSizing(logicalHeightLength.value());
 }
 
 void RenderBox::mapLocalToContainer(const RenderLayerModelObject* repaintContainer, TransformState& transformState, MapCoordinatesFlags mode, bool* wasFixed) const
 {
     if (repaintContainer == this)
         return;
 
     if (RenderView* v = view()) {
-        if (v->canUseLayoutStateForContainer(repaintContainer)) {
+        if (v->canMapUsingLayoutStateForContainer(repaintContainer)) {
             LayoutState* layoutState = v->layoutState();
             LayoutSize offset = layoutState->paintOffset() + locationOffset();
             if (style()->hasInFlowPosition() && layer())
                 offset += layer()->offsetForInFlowPosition();
             transformState.move(offset);
             return;
         }
     }
 
     bool containerSkipped;
@@ skipping 32 matching lines @@
     }
 
     mode &= ~ApplyContainerFlip;
 
     o->mapLocalToContainer(repaintContainer, transformState, mode, wasFixed);
 }
 
 void RenderBox::mapAbsoluteToLocalPoint(MapCoordinatesFlags mode, TransformState& transformState) const
 {
     // We don't expect to be called during layout.
-    ASSERT(!view() || !view()->layoutStateEnabled());
+    ASSERT(!view() || !view()->layoutStateCachedOffsetsEnabled());
 
     bool isFixedPos = style()->position() == FixedPosition;
     bool hasTransform = hasLayer() && layer()->transform();
     if (hasTransform && !isFixedPos) {
         // If this box has a transform, it acts as a fixed position container for fixed descendants,
         // and may itself also be fixed position. So propagate 'fixed' up only if this box is fixed position.
         mode &= ~IsFixed;
     } else if (isFixedPos)
         mode |= IsFixed;
 
@@ skipping 129 matching lines @@
     // Only when we cross a writing mode boundary will we have to possibly flipForWritingMode (to convert into a more appropriate
     // offset corner for the enclosing container).  This allows for a fully RL or BT document to repaint
     // properly even during layout, since the rect remains flipped all the way until the end.
     //
     // RenderView::computeRectForRepaint then converts the rect to physical coordinates.  We also convert to
     // physical when we hit a paintInvalidationContainer boundary. Therefore the final rect returned is always in the
     // physical coordinate space of the paintInvalidationContainer.
     RenderStyle* styleToUse = style();
     if (RenderView* v = view()) {
         // LayoutState is only valid for root-relative, non-fixed position repainting
-        if (v->canUseLayoutStateForContainer(paintInvalidationContainer) && styleToUse->position() != FixedPosition) {
+        if (v->canMapUsingLayoutStateForContainer(paintInvalidationContainer) && styleToUse->position() != FixedPosition) {
             LayoutState* layoutState = v->layoutState();
 
             if (layer() && layer()->transform())
                 rect = layer()->transform()->mapRect(pixelSnappedIntRect(rect));
 
             // We can't trust the bits on RenderObject, because this might be called while re-resolving style.
             if (styleToUse->hasInFlowPosition() && layer())
                 rect.move(layer()->offsetForInFlowPosition());
 
             rect.moveBy(location());
@@ skipping 2603 matching lines @@
         return 0;
 
     if (!layoutState && !flowThreadContainingBlock())
         return 0;
 
     RenderBlock* containerBlock = containingBlock();
     return containerBlock->offsetFromLogicalTopOfFirstPage() + logicalTop();
 }
 
 } // namespace WebCore