blink: Cleanup core class forward declarations

third_party/WebKit/Source/core/dom/shadow/ShadowRoot.h

 /*
  * Copyright (C) 2011 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 23 matching lines @@
 #include "core/dom/DocumentFragment.h"
 #include "core/dom/Element.h"
 #include "core/dom/TreeScope.h"
 
 namespace blink {
 
 class Document;
 class ElementShadow;
 class ExceptionState;
 class HTMLShadowElement;
-class HTMLSlotElement;
 class InsertionPoint;
 class ShadowRootRareDataV0;
 class SlotAssignment;
 
 enum class ShadowRootType { UserAgent, V0, Open, Closed };
 
 class CORE_EXPORT ShadowRoot final : public DocumentFragment, public TreeScope {
   DEFINE_WRAPPERTYPEINFO();
   USING_GARBAGE_COLLECTED_MIXIN(ShadowRoot);
 
@@ skipping 141 matching lines @@
                   treeScope,
                   treeScope->rootNode().isShadowRoot(),
                   treeScope.rootNode().isShadowRoot());
 DEFINE_TYPE_CASTS(TreeScope, ShadowRoot, shadowRoot, true, true);
 
 CORE_EXPORT std::ostream& operator<<(std::ostream&, const ShadowRootType&);
 
 }  // namespace blink
 
 #endif  // ShadowRoot_h