Revert of cc: Remove use of PassAs() and constructor-casting with scoped_ptr.

cc/layers/solid_color_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 "cc/layers/solid_color_layer.h"
 
 #include "cc/layers/solid_color_layer_impl.h"
 
 namespace cc {
 
 scoped_ptr<LayerImpl> SolidColorLayer::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
-  return SolidColorLayerImpl::Create(tree_impl, id());
+  return SolidColorLayerImpl::Create(tree_impl, id()).PassAs<LayerImpl>();
 }
 
 scoped_refptr<SolidColorLayer> SolidColorLayer::Create() {
   return make_scoped_refptr(new SolidColorLayer());
 }
 
 SolidColorLayer::SolidColorLayer()
     : Layer() {}
 
 SolidColorLayer::~SolidColorLayer() {}
 
 void SolidColorLayer::SetBackgroundColor(SkColor color) {
   SetContentsOpaque(SkColorGetA(color) == 255);
   Layer::SetBackgroundColor(color);
 }
 
 }  // namespace cc