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

third_party/WebKit/Source/core/css/CSSPaintImageGenerator.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 CSSPaintImageGenerator_h
+#define CSSPaintImageGenerator_h
+
+#include "core/CoreExport.h"
+#include "platform/geometry/IntSize.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class Document;
+class Image;
+
+// Produces a PaintGeneratedImage from a CSS Paint API callback.
+// https://drafts.css-houdini.org/css-paint-api/
+class CORE_EXPORT CSSPaintImageGenerator : public GarbageCollectedFinalized<CSSPaintImageGenerator> {
+public:
+    // This observer is used if the paint worklet doesn't have a javascript
+    // class registered with the correct name yet.
+    // paintImageGeneratorReady is called when the javascript class is
+    // registered and ready to use.
+    class Observer {
+    public:
+        virtual ~Observer() { };
+        virtual void paintImageGeneratorReady() = 0;
+    };
+
+    static CSSPaintImageGenerator* create(const String& name, Document&, Observer*);
+    virtual ~CSSPaintImageGenerator();
+
+    typedef CSSPaintImageGenerator* (*CSSPaintImageGeneratorCreateFunction)(const String&, Document&, Observer*);
+    static void init(CSSPaintImageGeneratorCreateFunction);
+
+    // Invokes the CSS Paint API 'paint' callback. May return a nullptr
+    // representing an invalid image if an error occurred.
+    virtual PassRefPtr<Image> paint(const IntSize&) = 0;
+
+    DEFINE_INLINE_VIRTUAL_TRACE() { }
+};
+
+} // namespace blink
+
+#endif // CSSPaintImageGenerator_h