Hook up CSSPaintValue::image to CSS Paint API callback.

third_party/WebKit/Source/modules/csspaint/CSSPaintImageGeneratorImpl.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 CSSPaintImageGeneratorImpl_h
+#define CSSPaintImageGeneratorImpl_h
+
+#include "bindings/core/v8/ScopedPersistent.h"
+#include "core/css/CSSPaintImageGenerator.h"
+#include "platform/geometry/IntSize.h"
+#include "platform/heap/Handle.h"
+#include <v8.h>
+
+namespace blink {
+
+class CSSPaintDefinition;
+class Document;
+class Image;
+
+class CSSPaintImageGeneratorImpl final : public CSSPaintImageGenerator {
+public:
+    static CSSPaintImageGenerator* create(const String& name, Document&, Observer*);
+    ~CSSPaintImageGeneratorImpl() override;
+
+    PassRefPtr<Image> paint(const IntSize&) final;
+
+    // Should be called from the PaintWorkletGlobalScope when a javascript class
+    // is registered with the same name.
+    void setDefinition(CSSPaintDefinition*);
+
+    DECLARE_VIRTUAL_TRACE();
+
+private:
+    CSSPaintImageGeneratorImpl(Observer*);
+    CSSPaintImageGeneratorImpl(CSSPaintDefinition*);
+
+    Member<CSSPaintDefinition> m_definition;
+    Observer* m_observer;

[haraken, 2016/04/08 04:31:19]

Can you make the Observer a GarbageCollectedMixin and use Member<Observer> here?

[ikilpatrick, 2016/04/08 18:43:21]

Made GarbageCollectedFinalized, see comment in CSSPaintValue.

+
+    // An instance of the paint class is owned and kept alive by this class.
+    ScopedPersistent<v8::Object> m_instance;

[haraken, 2016/04/08 04:31:19]

Who clears out m_instance when the worklet dies? How is it guaranteed that
m_instance does not cause a cycle?

[ikilpatrick, 2016/04/08 18:43:21]

Removed.

+};
+
+} // namespace blink
+
+#endif // CSSPaintImageGeneratorImpl_h