Have StyleElement API take Document as a reference

Source/core/html/HTMLStyleElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2010 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.
  *
@@ skipping 61 matching lines @@
     // overload from HTMLElement
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
     virtual void didNotifySubtreeInsertions(ContainerNode*) OVERRIDE;
     virtual void removedFrom(ContainerNode*) OVERRIDE;
     virtual void childrenChanged(bool changedByParser = false, Node* beforeChange = 0, Node* afterChange = 0, int childCountDelta = 0);
 
     virtual void finishParsingChildren();
 
     virtual bool isLoading() const { return StyleElement::isLoading(); }
-    virtual bool sheetLoaded() { return StyleElement::sheetLoaded(&document()); }
+    virtual bool sheetLoaded() { return StyleElement::sheetLoaded(document()); }
     virtual void notifyLoadedSheetAndAllCriticalSubresources(bool errorOccurred);
-    virtual void startLoadingDynamicSheet() { StyleElement::startLoadingDynamicSheet(&document()); }
+    virtual void startLoadingDynamicSheet() { StyleElement::startLoadingDynamicSheet(document()); }
 
     virtual void addSubresourceAttributeURLs(ListHashSet<KURL>&) const;
 
     virtual const AtomicString& media() const;
     virtual const AtomicString& type() const;
 
     void scopedAttributeChanged(bool);
     void registerWithScopingNode(bool);
     void unregisterWithScopingNode(ContainerNode*);
 
@@ skipping 16 matching lines @@
 
 inline HTMLStyleElement* toHTMLStyleElement(Node* node)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!node || node->hasTagName(HTMLNames::styleTag));
     return static_cast<HTMLStyleElement*>(node);
 }
 
 } //namespace
 
 #endif