Remove StyleEngine.h include from RenderObject.h

Source/core/css/AffectedByFocusTest.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/HTMLNames.h"
 #include "core/dom/Element.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/NodeRenderStyle.h"
+#include "core/dom/StyleEngine.h"
 #include "core/frame/FrameView.h"
 #include "core/html/HTMLDocument.h"
 #include "core/html/HTMLElement.h"
 #include "core/testing/DummyPageHolder.h"
 #include <gtest/gtest.h>
 
 using namespace WebCore;
 using namespace HTMLNames;
 
 namespace {
@@ skipping 287 matching lines @@
 
     document().getElementById("d")->focus();
     document().view()->updateLayoutAndStyleIfNeededRecursive();
 
     unsigned accessCount = document().styleEngine()->resolverAccessCount() - startCount;
 
     ASSERT_EQ(1U, accessCount);
 }
 
 } // namespace