Return reference from styleEngine() accessor.

Source/core/html/imports/HTMLImportTreeRoot.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/html/imports/HTMLImportTreeRoot.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/StyleEngine.h"
 #include "core/frame/LocalFrame.h"
@@ skipping 24 matching lines @@
 #endif
 }
 
 Document* HTMLImportTreeRoot::document() const
 {
     return m_document;
 }
 
 bool HTMLImportTreeRoot::isDone() const
 {
-    return !m_document->parsing() && m_document->styleEngine()->haveStylesheetsLoaded();
+    return !m_document->parsing() && m_document->styleEngine().haveStylesheetsLoaded();
 }
 
 void HTMLImportTreeRoot::stateWillChange()
 {
     scheduleRecalcState();
 }
 
 void HTMLImportTreeRoot::stateDidChange()
 {
     HTMLImport::stateDidChange();
@@ skipping 45 matching lines @@
 }
 
 DEFINE_TRACE(HTMLImportTreeRoot)
 {
     visitor->trace(m_document);
     visitor->trace(m_imports);
     HTMLImport::trace(visitor);
 }
 
 }