Remove forward declarations from Source/core/dom/custom

Source/core/dom/custom/CustomElementProcessingStack.h

 /*
  * Copyright (C) 2013 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
@@ skipping 18 matching lines @@
  */
 
 #ifndef CustomElementProcessingStack_h
 #define CustomElementProcessingStack_h
 
 #include "core/dom/custom/CustomElementCallbackQueue.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
-class CustomElementScheduler;
-
 class CustomElementProcessingStack {
     WTF_MAKE_NONCOPYABLE(CustomElementProcessingStack);
 public:
     // This is stack allocated in many DOM callbacks. Make it cheap.
     class CallbackDeliveryScope {
     public:
         CallbackDeliveryScope()
             : m_savedElementQueueStart(s_elementQueueStart)
         {
             s_elementQueueStart = s_elementQueueEnd;
@@ skipping 42 matching lines @@
     static void processElementQueueAndPop();
     void processElementQueueAndPop(size_t start, size_t end);
 
     // The processing stack, flattened. Element queues lower in the
     // stack appear toward the head of the vector. The first element
     // is a null sentinel value.
     static const size_t kNumSentinels = 1;
     Vector<CustomElementCallbackQueue*> m_flattenedProcessingStack;
 };
 
-}
+} // namespace blink
 
 #endif // CustomElementProcessingStack_h