Remove unused includes from core/{editing,fileapi,history,html}

Source/core/html/canvas/WebGLShader.h

 /*
  * Copyright (C) 2009 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 11 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
 #ifndef WebGLShader_h
 #define WebGLShader_h
 
 #include "bindings/v8/ScriptWrappable.h"
 #include "core/html/canvas/WebGLSharedObject.h"
 #include "wtf/PassRefPtr.h"
-#include "wtf/RefCounted.h"
 
 namespace WebCore {
 
 class WebGLShader : public WebGLSharedObject, public ScriptWrappable {
 public:
     virtual ~WebGLShader();
 
     static PassRefPtr<WebGLShader> create(WebGLRenderingContext*, GC3Denum);
 
     GC3Denum getType() const { return m_type; }
     const String& getSource() const { return m_source; }
 
     void setSource(const String& source) { m_source = source; }
 
 private:
     WebGLShader(WebGLRenderingContext*, GC3Denum);
 
     virtual void deleteObjectImpl(GraphicsContext3D*, Platform3DObject);
 
     virtual bool isShader() const { return true; }
 
     GC3Denum m_type;
     String m_source;
 };
 
 } // namespace WebCore
 
 #endif // WebGLShader_h