Return reference from styleEngine() accessor.

Source/core/dom/StyleEngine.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 40 matching lines @@
 class StyleRuleFontFace;
 class StyleSheet;
 class StyleSheetContents;
 
 class StyleEngine final : public CSSFontSelectorClient  {
     WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
 
     class IgnoringPendingStylesheet : public TemporaryChange<bool> {
     public:
-        IgnoringPendingStylesheet(StyleEngine* engine)
-            : TemporaryChange<bool>(engine->m_ignorePendingStylesheets, true)
+        IgnoringPendingStylesheet(StyleEngine& engine)
+            : TemporaryChange<bool>(engine.m_ignorePendingStylesheets, true)
         {
         }
     };
 
     friend class IgnoringPendingStylesheet;
 
     static PassOwnPtrWillBeRawPtr<StyleEngine> create(Document& document) { return adoptPtrWillBeNoop(new StyleEngine(document)); }
 
     ~StyleEngine();
 
@@ skipping 224 matching lines @@
 
     RefPtrWillBeMember<CSSFontSelector> m_fontSelector;
 
     WillBeHeapHashMap<AtomicString, RawPtrWillBeMember<StyleSheetContents> > m_textToSheetCache;
     WillBeHeapHashMap<RawPtrWillBeMember<StyleSheetContents>, AtomicString> m_sheetToTextCache;
 };
 
 }
 
 #endif