Add APIs for dynamic display lists, using SkDrawable and SkPictureRecorder::endRecordingAsDrawable.

sky/engine/core/painting/Drawable.h

Index: sky/engine/core/painting/Drawable.h
diff --git a/sky/engine/core/painting/Drawable.h b/sky/engine/core/painting/Drawable.h
new file mode 100644
index 0000000000000000000000000000000000000000..1ee2fddf05a60cd35cc743bbe4ff4835ca3a5565
--- /dev/null
+++ b/sky/engine/core/painting/Drawable.h
@@ -0,0 +1,32 @@
+// Copyright 2015 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 SKY_ENGINE_CORE_DRAWABLE_PICTURE_H_
+#define SKY_ENGINE_CORE_DRAWABLE_PICTURE_H_
+
+#include "sky/engine/core/painting/Picture.h"
+#include "sky/engine/tonic/dart_wrappable.h"
+#include "sky/engine/wtf/PassRefPtr.h"
+#include "sky/engine/wtf/RefCounted.h"
+#include "third_party/skia/include/core/SkDrawable.h"
+
+namespace blink {
+
+class Drawable : public RefCounted<Drawable>, public DartWrappable {
+    DEFINE_WRAPPERTYPEINFO();
+public:
+    static PassRefPtr<Drawable> create(PassRefPtr<SkDrawable> skDrawable);
+    ~Drawable() override;
+
+    PassRefPtr<Picture> newPictureSnapshot();
+    SkDrawable* toSkia() const { return m_drawable.get(); }
+
+private:
+    explicit Drawable(PassRefPtr<SkDrawable> skDrawable);
+    RefPtr<SkDrawable> m_drawable;
+};
+
+} // namespace blink
+
+#endif  // SKY_ENGINE_CORE_DRAWABLE_PICTURE_H_