Make it possible to custom-paint without an Element.

sky/engine/core/painting/PictureRecorder.cpp

+// 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.
+
+#include "sky/engine/config.h"
+#include "sky/engine/core/painting/PictureRecorder.h"
+
+#include "sky/engine/core/painting/Picture.h"
+
+namespace blink {
+
+PassRefPtr<PictureRecorder> PictureRecorder::create(double width, double height)
+{
+    return adoptRef(new PictureRecorder(FloatSize(width, height)));
+}
+
+PictureRecorder::PictureRecorder(const FloatSize& size)
+    : Canvas(size)
+{
+}
+
+PictureRecorder::~PictureRecorder()
+{
+}
+
+PassRefPtr<Picture> PictureRecorder::endRecording()
+{
+    if (!isRecording())
+        return nullptr;
+    return Picture::create(finishRecording());
+}
+
+} // namespace blink