[DONT COMMIT] PaintWorklet: Move paintWorklet from 'window' to 'CSS'

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 "modules/ModulesExport.h"
 #include "modules/csspaint/PaintWorkletGlobalScopeProxy.h"
 #include "modules/csspaint/PaintWorkletPendingGeneratorRegistry.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class CSSPaintDefinition;
 class CSSPaintImageGeneratorImpl;
 
 // Manages a paint worklet:
 // https://drafts.css-houdini.org/css-paint-api/#dom-css-paintworklet
-class MODULES_EXPORT PaintWorklet final : public Worklet {
+class MODULES_EXPORT PaintWorklet final : public Worklet,
+                                          public Supplement<LocalDOMWindow> {
+  USING_GARBAGE_COLLECTED_MIXIN(PaintWorklet);
   WTF_MAKE_NONCOPYABLE(PaintWorklet);
 
  public:
+  static PaintWorklet* From(LocalDOMWindow&);
   static PaintWorklet* Create(LocalFrame*);
   ~PaintWorklet() override;
 
   CSSPaintDefinition* FindDefinition(const String& name);
   void AddPendingGenerator(const String& name, CSSPaintImageGeneratorImpl*);
 
   DECLARE_VIRTUAL_TRACE();
 
  private:
   friend class PaintWorkletTest;
 
   explicit PaintWorklet(LocalFrame*);
 
   // Implements Worklet.
   bool NeedsToCreateGlobalScope() final;
   std::unique_ptr<WorkletGlobalScopeProxy> CreateGlobalScope() final;
 
   Member<PaintWorkletPendingGeneratorRegistry> pending_generator_registry_;
 
   // TODO(style-dev): Implement the "document paint definition" concept:
   // https://drafts.css-houdini.org/css-paint-api/#document-paint-definition
   // (https://crbug.com/578252)
+
+  static const char* SupplementName();
 };
 
 }  // namespace blink
 
 #endif  // PaintWorklet_h