Don't include LayoutObject-derived headers where not needed.

third_party/WebKit/Source/core/dom/ElementRareData.h

 /*
  * Copyright (C) 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Smith <catfish.man@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 19 matching lines @@
 #include "core/dom/DatasetDOMStringMap.h"
 #include "core/dom/NamedNodeMap.h"
 #include "core/dom/NodeIntersectionObserverData.h"
 #include "core/dom/NodeRareData.h"
 #include "core/dom/PseudoElement.h"
 #include "core/dom/PseudoElementData.h"
 #include "core/dom/custom/CustomElementDefinition.h"
 #include "core/dom/custom/V0CustomElementDefinition.h"
 #include "core/dom/shadow/ElementShadow.h"
 #include "core/html/ClassList.h"
-#include "core/layout/LayoutObject.h"
-#include "core/style/StyleInheritedData.h"
 #include "platform/heap/Handle.h"
 #include "wtf/HashSet.h"
 #include <memory>
 
 namespace blink {
 
+class LayoutObject;
 class CompositorProxiedPropertySet;
 class ResizeObservation;
 class ResizeObserver;
 
 class ElementRareData : public NodeRareData {
  public:
   static ElementRareData* create(LayoutObject* layoutObject) {
     return new ElementRareData(layoutObject);
   }
 
@@ skipping 217 matching lines @@
 inline CompositorProxiedPropertySet&
 ElementRareData::ensureCompositorProxiedPropertySet() {
   if (!m_proxiedProperties)
     m_proxiedProperties = CompositorProxiedPropertySet::create();
   return *m_proxiedProperties;
 }
 
 }  // namespace blink
 
 #endif  // ElementRareData_h