cc: Add some impl-side painting stub classes and APIs

cc/picture_layer.cc

+// Copyright 2012 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 "config.h"
+
+#include "cc/picture_layer.h"
+#include "cc/picture_layer_impl.h"
+
+namespace cc {
+
+scoped_refptr<PictureLayer> PictureLayer::create(ContentLayerClient* client) {
+  return make_scoped_refptr(new PictureLayer(client));
+}
+
+PictureLayer::PictureLayer(ContentLayerClient* client) :
+  client_(client) {
+}
+
+PictureLayer::~PictureLayer() {
+}
+
+bool PictureLayer::drawsContent() const {
+  return Layer::drawsContent() && client_;
+}
+
+scoped_ptr<LayerImpl> PictureLayer::createLayerImpl() {
+  return PictureLayerImpl::create(id()).PassAs<LayerImpl>();
+}
+
+void PictureLayer::pushPropertiesTo(LayerImpl* baseLayerImpl) {
+  PictureLayerImpl* layerImpl = static_cast<PictureLayerImpl*>(baseLayerImpl);
+  picture_.pushPropertiesTo(layerImpl->picture_);
+}
+
+}  // namespace cc