Have Node::document() return a reference instead of a pointer

Source/core/dom/NodeRenderingContext.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2011 Google 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
@@ skipping 61 matching lines @@
     if (element && element->shouldBeReparentedUnderRenderView(m_style.get())) {
         // FIXME: Reparented renderers not in the top layer should probably be
         // ordered in DOM tree order. We don't have a good way to do that yet,
         // since NodeRenderingTraversal isn't aware of reparenting. It's safe to
         // just append for now; it doesn't disrupt the top layer rendering as
         // the layer collection in RenderLayer only requires that top layer
         // renderers are orderered correctly relative to each other.
         if (!element->isInTopLayer())
             return 0;
 
-        const Vector<RefPtr<Element> >& topLayerElements = element->document()->topLayerElements();
+        const Vector<RefPtr<Element> >& topLayerElements = element->document().topLayerElements();
         size_t position = topLayerElements.find(element);
         ASSERT(position != notFound);
         for (size_t i = position + 1; i < topLayerElements.size(); ++i) {
             if (RenderObject* renderer = topLayerElements[i]->renderer())
                 return renderer;
         }
         return 0;
     }
 
     if (m_parentFlowRenderer)
@@ skipping 44 matching lines @@
 
     if (m_node->isElementNode() && toElement(m_node)->shouldBeReparentedUnderRenderView(m_style.get())) {
         // The parent renderer of reparented elements is the RenderView, but only
         // if the normal parent would have had a renderer.
         // FIXME: This behavior isn't quite right as the spec for top layer
         // only talks about display: none ancestors so putting a <dialog> inside
         // an <optgroup> seems like it should still work even though this check
         // will prevent it.
         if (!m_renderingParent || !m_renderingParent->renderer())
             return 0;
-        return m_node->document()->renderView();
+        return m_node->document().renderView();
     }
 
     if (m_parentFlowRenderer)
         return m_parentFlowRenderer;
 
     return m_renderingParent ? m_renderingParent->renderer() : 0;
 }
 
 bool NodeRenderingContext::shouldCreateRenderer() const
 {
@@ skipping 34 matching lines @@
 void NodeRenderingContext::moveToFlowThreadIfNeeded()
 {
     if (!RuntimeEnabledFeatures::cssRegionsEnabled())
         return;
 
     Element* element = toElement(m_node);
 
     if (!element->shouldMoveToFlowThread(m_style.get()))
         return;
 
-    ASSERT(m_node->document()->renderView());
-    FlowThreadController* flowThreadController = m_node->document()->renderView()->flowThreadController();
+    ASSERT(m_node->document().renderView());
+    FlowThreadController* flowThreadController = m_node->document().renderView()->flowThreadController();
     m_parentFlowRenderer = flowThreadController->ensureRenderFlowThreadWithName(m_style->flowThread());
     flowThreadController->registerNamedFlowContentNode(m_node, m_parentFlowRenderer);
 }
 
 void NodeRenderingContext::createRendererForElementIfNeeded()
 {
     ASSERT(!m_node->renderer());
 
     Element* element = toElement(m_node);
 
@@ skipping 26 matching lines @@
 
     // Make sure the RenderObject already knows it is going to be added to a RenderFlowThread before we set the style
     // for the first time. Otherwise code using inRenderFlowThread() in the styleWillChange and styleDidChange will fail.
     newRenderer->setFlowThreadState(parentRenderer->flowThreadState());
 
     RenderObject* nextRenderer = this->nextRenderer();
     element->setRenderer(newRenderer);
     newRenderer->setAnimatableStyle(m_style.release()); // setAnimatableStyle() can depend on renderer() already being set.
 
     if (FullscreenElementStack::isActiveFullScreenElement(element)) {
-        newRenderer = RenderFullScreen::wrapRenderer(newRenderer, parentRenderer, element->document());
+        newRenderer = RenderFullScreen::wrapRenderer(newRenderer, parentRenderer, &element->document());
         if (!newRenderer)
             return;
     }
 
     // Note: Adding newRenderer instead of renderer(). renderer() may be a child of newRenderer.
     parentRenderer->addChild(newRenderer, nextRenderer);
 }
 
 void NodeRenderingContext::createRendererForTextIfNeeded()
 {
     ASSERT(!m_node->renderer());
 
     Text* textNode = toText(m_node);
 
     if (!shouldCreateRenderer())
         return;
 
     RenderObject* parentRenderer = this->parentRenderer();
 
     if (m_parentDetails.resetStyleInheritance())
-        m_style = textNode->document()->styleResolver()->defaultStyleForElement();
+        m_style = textNode->document().styleResolver()->defaultStyleForElement();
     else
         m_style = parentRenderer->style();
 
     if (!textNode->textRendererIsNeeded(*this))
         return;
 
     RenderText* newRenderer = textNode->createTextRenderer(m_style.get());
     if (!parentRenderer->isChildAllowed(newRenderer, m_style.get())) {
         newRenderer->destroy();
         return;
     }
 
     // Make sure the RenderObject already knows it is going to be added to a RenderFlowThread before we set the style
     // for the first time. Otherwise code using inRenderFlowThread() in the styleWillChange and styleDidChange will fail.
     newRenderer->setFlowThreadState(parentRenderer->flowThreadState());
 
     RenderObject* nextRenderer = this->nextRenderer();
     textNode->setRenderer(newRenderer);
     // Parent takes care of the animations, no need to call setAnimatableStyle.
     newRenderer->setStyle(m_style.release());
     parentRenderer->addChild(newRenderer, nextRenderer);
 }
 
 }