Clean up forward declarations in Source/core/html

Source/core/html/shadow/SliderThumbElement.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010 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.
@@ skipping 21 matching lines @@
 #ifndef SliderThumbElement_h
 #define SliderThumbElement_h
 
 #include "core/HTMLNames.h"
 #include "core/html/HTMLDivElement.h"
 #include "core/rendering/RenderBlockFlow.h"
 #include "wtf/Forward.h"
 
 namespace blink {
 
-class HTMLElement;
 class HTMLInputElement;
 class Event;
-class FloatPoint;
 
 class SliderThumbElement FINAL : public HTMLDivElement {
 public:
     static PassRefPtrWillBeRawPtr<SliderThumbElement> create(Document&);
 
     void setPositionFromValue();
 
     void dragFrom(const LayoutPoint&);
     virtual void defaultEventHandler(Event*) OVERRIDE;
     virtual bool willRespondToMouseMoveEvents() OVERRIDE;
@@ skipping 31 matching lines @@
 
 private:
     explicit SliderContainerElement(Document&);
     virtual RenderObject* createRenderer(RenderStyle*) OVERRIDE;
     virtual const AtomicString& shadowPseudoId() const OVERRIDE;
 };
 
 }
 
 #endif