Convert //cc from scoped_ptr to std::unique_ptr.

cc/test/layer_tree_json_parser.cc

 // Copyright 2013 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/test/layer_tree_json_parser.h"
 
 #include <stddef.h>
 
 #include "base/test/values_test_util.h"
 #include "base/values.h"
@@ skipping 148 matching lines @@
   if (!success)
     return NULL;
 
   return new_layer;
 }
 
 }  // namespace
 
 scoped_refptr<Layer> ParseTreeFromJson(std::string json,
                                        ContentLayerClient* content_client) {
-  scoped_ptr<base::Value> val = base::test::ParseJson(json);
+  std::unique_ptr<base::Value> val = base::test::ParseJson(json);
   return ParseTreeFromValue(val.get(), content_client);
 }
 
 }  // namespace cc