Have Document::accessSVGExtensions() return a reference

Source/core/rendering/svg/SVGResources.cpp

 /*
  * Copyright (C) Research In Motion Limited 2010. 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 168 matching lines @@
         return 0;
     }
 
     RenderSVGResourceType resourceType = container->resourceType();
     if (resourceType != PatternResourceType && resourceType != LinearGradientResourceType && resourceType != RadialGradientResourceType)
         return 0;
 
     return container;
 }
 
-static inline void registerPendingResource(SVGDocumentExtensions* extensions, const AtomicString& id, SVGElement* element)
+static inline void registerPendingResource(SVGDocumentExtensions& extensions, const AtomicString& id, SVGElement* element)
 {
     ASSERT(element);
-    extensions->addPendingResource(id, element);
+    extensions.addPendingResource(id, element);
 }
 
 bool SVGResources::hasResourceData() const
 {
     return !m_clipperFilterMaskerData
         && !m_markerData
         && !m_fillStrokeData
         && !m_linkedResource;
 }
 
@@ skipping 13 matching lines @@
     Node* node = object->node();
     ASSERT(node);
     ASSERT_WITH_SECURITY_IMPLICATION(node->isSVGElement());
 
     SVGElement* element = toSVGElement(node);
     if (!element)
         return nullptr;
 
     Document& document = object->document();
 
-    SVGDocumentExtensions* extensions = document.accessSVGExtensions();
-    ASSERT(extensions);
+    SVGDocumentExtensions& extensions = document.accessSVGExtensions();
 
     const AtomicString& tagName = element->localName();
     if (tagName.isNull())
         return nullptr;
 
     OwnPtr<SVGResources> resources;
     if (clipperFilterMaskerTags().contains(tagName)) {
         if (style->hasClipper()) {
             AtomicString id = style->clipperResource();
             if (!ensureResources(resources)->setClipper(getRenderSVGResourceById<RenderSVGResourceClipper>(document, id)))
@@ skipping 462 matching lines @@
         if (RenderSVGResourceContainer* stroke = m_fillStrokeData->stroke)
             fprintf(stderr, " |-> Stroke     : %p (node=%p)\n", stroke, stroke->element());
     }
 
     if (m_linkedResource)
         fprintf(stderr, " |-> xlink:href : %p (node=%p)\n", m_linkedResource, m_linkedResource->element());
 }
 #endif
 
 }