Make LayoutState always be RAII

Source/core/rendering/RenderView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 143 matching lines @@
     if (!positionedDescendants)
         return;
     TrackedRendererListHashSet::iterator end = positionedDescendants->end();
     for (TrackedRendererListHashSet::iterator it = positionedDescendants->begin(); it != end; ++it) {
         RenderBox* box = *it;
         if (isHTMLDialogElement(box->node()))
             positionDialog(box);
     }
 }
 
-void RenderView::layoutContent(const LayoutState& state)
+void RenderView::layoutContent()
 {
     ASSERT(needsLayout());
 
     LayoutRectRecorder recorder(*this);
     RenderBlockFlow::layout();
 
     if (RuntimeEnabledFeatures::dialogElementEnabled())
         positionDialogs();
 
 #ifndef NDEBUG
-    checkLayoutState(state);
+    checkLayoutState();
 #endif
 }
 
 #ifndef NDEBUG
-void RenderView::checkLayoutState(const LayoutState& state)
+void RenderView::checkLayoutState()
 {
     if (!RuntimeEnabledFeatures::repaintAfterLayoutEnabled()) {
         ASSERT(layoutDeltaMatches(LayoutSize()));
     }
     ASSERT(!m_layoutStateDisableCount);
-    ASSERT(m_layoutState == &state);
+    ASSERT(!m_layoutState->m_next);
 }
 #endif
 
-void RenderView::initializeLayoutState(LayoutState& state)
+void RootLayoutStateScope::initializeLayoutState()
 {
-    state.m_clipped = false;
-    state.m_pageLogicalHeight = m_pageLogicalHeight;
-    state.m_pageLogicalHeightChanged = m_pageLogicalHeightChanged;
-    state.m_isPaginated = state.m_pageLogicalHeight;
+    m_rootLayoutState.m_clipped = false;
+    m_rootLayoutState.m_pageLogicalHeight = m_view.m_pageLogicalHeight;
+    m_rootLayoutState.m_pageLogicalHeightChanged = m_view.m_pageLogicalHeightChanged;
+    m_rootLayoutState.m_isPaginated = m_rootLayoutState.m_pageLogicalHeight;
 }
 
 void RenderView::layout()
 {
     if (!document().paginated())
         setPageLogicalHeight(0);
 
     if (shouldUsePrintingLayout())
         m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = logicalWidth();
 
@@ skipping 15 matching lines @@
         }
 
         if (document().svgExtensions())
             document().accessSVGExtensions().invalidateSVGRootsWithRelativeLengthDescendents(&layoutScope);
     }
 
     ASSERT(!m_layoutState);
     if (!needsLayout())
         return;
 
-    LayoutState state;
-    initializeLayoutState(state);
+    RootLayoutStateScope rootLayoutStateScope(*this);
 
     m_pageLogicalHeightChanged = false;
-    m_layoutState = &state;
 
-    layoutContent(state);
+    layoutContent();
 
 #ifndef NDEBUG
-    checkLayoutState(state);
+    checkLayoutState();
 #endif
-    m_layoutState = 0;
     clearNeedsLayout();
 }
 
 void RenderView::mapLocalToContainer(const RenderLayerModelObject* repaintContainer, TransformState& transformState, MapCoordinatesFlags mode, bool* wasFixed) const
 {
     ASSERT_UNUSED(wasFixed, !wasFixed || *wasFixed == static_cast<bool>(mode & IsFixed));
 
     if (!repaintContainer && mode & UseTransforms && shouldUseTransformFromContainer(0)) {
         TransformationMatrix t;
         getTransformFromContainer(0, LayoutSize(), t);
@@ skipping 716 matching lines @@
     return viewWidth(IncludeScrollbars) / scale;
 }
 
 double RenderView::layoutViewportHeight() const
 {
     float scale = m_frameView ? m_frameView->frame().pageZoomFactor() : 1;
     return viewHeight(IncludeScrollbars) / scale;
 }
 
 } // namespace WebCore