Worklet: Separate Worklet into MainThreadWorklet and ThreadedWorklet

third_party/WebKit/Source/modules/csspaint/PaintWorklet.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 PaintWorklet_h
 #define PaintWorklet_h
 
-#include "core/workers/Worklet.h"
+#include "core/workers/MainThreadWorklet.h"
 #include "modules/ModulesExport.h"
 #include "modules/csspaint/PaintWorkletGlobalScope.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class CSSPaintDefinition;
 class CSSPaintImageGeneratorImpl;
 
-class MODULES_EXPORT PaintWorklet final : public Worklet {
+class MODULES_EXPORT PaintWorklet final : public MainThreadWorklet {
   WTF_MAKE_NONCOPYABLE(PaintWorklet);
 
  public:
   static PaintWorklet* Create(LocalFrame*);
   ~PaintWorklet() override;
 
   PaintWorkletGlobalScope* GetWorkletGlobalScopeProxy() const final;
   CSSPaintDefinition* FindDefinition(const String& name);
   void AddPendingGenerator(const String& name, CSSPaintImageGeneratorImpl*);
 
   DECLARE_VIRTUAL_TRACE();
 
  private:
   explicit PaintWorklet(LocalFrame*);
 
   Member<PaintWorkletGlobalScope> paint_worklet_global_scope_;
 };
 
 }  // namespace blink
 
 #endif  // PaintWorklet_h