blink: Cleanup class forward declarations

third_party/WebKit/Source/wtf/VectorTraits.h

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 11 matching lines @@
 #define WTF_VectorTraits_h
 
 #include "wtf/RefPtr.h"
 #include "wtf/TypeTraits.h"
 #include <memory>
 #include <type_traits>
 #include <utility>
 
 namespace WTF {
 
-class AtomicString;
-
 template <typename T>
 struct VectorTraitsBase {
   static const bool needsDestruction = !IsTriviallyDestructible<T>::value;
 
   static const bool canInitializeWithMemset =
       IsTriviallyDefaultConstructible<T>::value;
   // true iff memset(slot, 0, size) constructs an unused slot value that is
   // valid for Oilpan to trace and if the value needs destruction, its
   // destructor can be invoked over. The zero'ed value representing an unused
   // slot in the vector's backing storage; it does not have to be equal to
@@ skipping 135 matching lines @@
   template <>                                                       \
   struct VectorTraits<ClassName> : VectorTraitsBase<ClassName> {    \
     static const bool canClearUnusedSlotsWithMemset = true;         \
   };                                                                \
   }
 
 using WTF::VectorTraits;
 using WTF::SimpleClassVectorTraits;
 
 #endif  // WTF_VectorTraits_h