Implement PaintWorkletGlobalScope#registerPaint() for the CSS Paint API

third_party/WebKit/Source/modules/csspaint/CSSPaintDefinition.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 CSSPaintDefinition_h
+#define CSSPaintDefinition_h
+
+#include "bindings/core/v8/ScopedPersistent.h"
+#include "platform/geometry/IntSize.h"
+#include "platform/heap/Handle.h"
+#include <v8.h>
+
+namespace blink {
+
+class ScriptState;
+
+class CSSPaintDefinition final : public GarbageCollectedFinalized<CSSPaintDefinition> {
+public:
+    static RawPtr<CSSPaintDefinition> create(ScriptState*, v8::Local<v8::Function> constructor, v8::Local<v8::Function> paint);
+    virtual ~CSSPaintDefinition();
+
+    v8::Local<v8::Function> paintFunctionForTesting(v8::Isolate* isolate) { return m_paint.newLocal(isolate); }
+
+    DEFINE_INLINE_TRACE() { };
+
+private:
+    CSSPaintDefinition(ScriptState*, v8::Local<v8::Function> constructor, v8::Local<v8::Function> paint);
+
+    RefPtr<ScriptState> m_scriptState;
+
+    // This object keeps the constructor and paint functions alive. This object
+    // needs to be destroyed to break a reference cycle between it and the
+    // PaintWorkletGlobalScope.
+    ScopedPersistent<v8::Function> m_constructor;
+    ScopedPersistent<v8::Function> m_paint;
+};
+
+} // namespace blink
+
+#endif // CSSPaintDefinition_h