blink: Cleanup class forward declarations

third_party/WebKit/Source/modules/canvas/HTMLCanvasElementModule.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef HTMLCanvasElementModule_h
 #define HTMLCanvasElementModule_h
 
 #include "core/html/HTMLCanvasElement.h"
 #include "modules/ModulesExport.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class CanvasContextCreationAttributes;
 class HTMLCanvasElement;
-class ScriptState;
 class OffscreenCanvas;
 
 class MODULES_EXPORT HTMLCanvasElementModule {
   STATIC_ONLY(HTMLCanvasElementModule);
 
   friend class HTMLCanvasElementModuleTest;
 
  public:
   static void getContext(HTMLCanvasElement&,
                          const String&,
                          const CanvasContextCreationAttributes&,
                          ExceptionState&,
                          RenderingContext&);
   static OffscreenCanvas* transferControlToOffscreen(HTMLCanvasElement&,
                                                      ExceptionState&);
 
  private:
   static OffscreenCanvas* transferControlToOffscreenInternal(HTMLCanvasElement&,
                                                              ExceptionState&);
 };
 }
 
 #endif