Return reference from styleEngine() accessor.

Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 2648 matching lines @@
     }
     return false;
 }
 
 void Element::createPseudoElementIfNeeded(PseudoId pseudoId)
 {
     if (isPseudoElement())
         return;
 
     // Document::ensureStyleResolver is not inlined and shows up on profiles, avoid it here.
-    StyleEngine* engine = document().styleEngine();
-    RefPtrWillBeRawPtr<PseudoElement> element = engine->ensureResolver().createPseudoElementIfNeeded(*this, pseudoId);
+    RefPtrWillBeRawPtr<PseudoElement> element = document().styleEngine().ensureResolver().createPseudoElementIfNeeded(*this, pseudoId);
     if (!element)
         return;
 
     if (pseudoId == BACKDROP)
         document().addToTopLayer(element.get(), this);
     element->insertedInto(this);
     element->attach();
 
     InspectorInstrumentation::pseudoElementCreated(element.get());
 
@@ skipping 700 matching lines @@
 {
 #if ENABLE(OILPAN)
     if (hasRareData())
         visitor->trace(elementRareData());
     visitor->trace(m_elementData);
 #endif
     ContainerNode::trace(visitor);
 }
 
 } // namespace blink