Decouple Canvas from DisplayList and map Picture and PictureRecorder more directly to their Skia co…

sky/engine/core/painting/PictureRecorder.h

 // 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_PAINTING_PICTURERECORDER_H_
 #define SKY_ENGINE_CORE_PAINTING_PICTURERECORDER_H_
 
 #include "sky/engine/core/painting/Canvas.h"
+#include "third_party/skia/include/core/SkPictureRecorder.h"
 
 namespace blink {
 
 class Picture;
 
-class PictureRecorder : public Canvas {
+class PictureRecorder : public RefCounted<PictureRecorder>,
+                        public DartWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    ~PictureRecorder() override;
-    static PassRefPtr<PictureRecorder> create(double width, double height);
+    static PassRefPtr<PictureRecorder> create()
+    {
+        return adoptRef(new PictureRecorder());
+    }
 
+    ~PictureRecorder();
+
+    PassRefPtr<Canvas> beginRecording(double width, double height);
     PassRefPtr<Picture> endRecording();
+    bool isRecording() { return m_canvas != nullptr && m_canvas->isRecording(); }

[abarth-chromium, 2015/06/20 00:50:29]

It is every possible for m_canvas != nullptr and !m_canvas->isRecording() ?

+
+    void setCanvas(PassRefPtr<Canvas> canvas) { m_canvas = canvas; }

[abarth-chromium, 2015/06/20 00:50:29]

This function doesn't make much sense.  What does it mean to set the canvas on a
PictureRecorder?  PictureRecorder is a thing that produces a canvas.

 
 private:
-    PictureRecorder(const FloatSize& size);
+        PictureRecorder();
+
+        OwnPtr<SkPictureRecorder> m_pictureRecorder;
+        RefPtr<Canvas> m_canvas;
 };
 
 } // namespace blink
 
 #endif  // SKY_ENGINE_CORE_PAINTING_PICTURERECORDER_H_