Return reference from styleEngine() accessor.

Source/core/inspector/InspectorCSSAgent.cpp

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 1269 matching lines @@
     if (!node->isElementNode()) {
         *errorString = "Not an element node";
         return nullptr;
     }
     return toElement(node);
 }
 
 // static
 void InspectorCSSAgent::collectAllDocumentStyleSheets(Document* document, WillBeHeapVector<RawPtrWillBeMember<CSSStyleSheet> >& result)
 {
-    const WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet> > activeStyleSheets = document->styleEngine()->activeStyleSheetsForInspector();
+    const WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet>> activeStyleSheets = document->styleEngine().activeStyleSheetsForInspector();
     for (const auto& style : activeStyleSheets) {
         CSSStyleSheet* styleSheet = style.get();
         InspectorCSSAgent::collectStyleSheets(styleSheet, result);
     }
 }
 
 // static
 void InspectorCSSAgent::collectStyleSheets(CSSStyleSheet* styleSheet, WillBeHeapVector<RawPtrWillBeMember<CSSStyleSheet> >& result)
 {
     result.append(styleSheet);
@@ skipping 273 matching lines @@
     visitor->trace(m_invalidatedDocuments);
     visitor->trace(m_nodeToInspectorStyleSheet);
     visitor->trace(m_documentToViaInspectorStyleSheet);
 #endif
     visitor->trace(m_inspectorUserAgentStyleSheet);
     InspectorBaseAgent::trace(visitor);
 }
 
 } // namespace blink