Add scoped_ptr-safe base::Value to Dictionary/List conversion functions.

extensions/common/features/json_feature_provider_source.cc

 // Copyright 2014 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 "extensions/common/features/json_feature_provider_source.h"
 
 #include "base/json/json_reader.h"
 #include "base/logging.h"
 #include "ui/base/resource/resource_bundle.h"
 
@@ skipping 12 matching lines @@
                                          .as_string();
   int error_code = 0;
   std::string error_message;
   scoped_ptr<base::Value> value(base::JSONReader::ReadAndReturnError(
       features_file, base::JSON_PARSE_RFC, &error_code, &error_message));
   DCHECK(value) << "Could not load features: " << name_ << " " << error_message;
 
   scoped_ptr<base::DictionaryValue> value_as_dict;
   if (value) {
     CHECK(value->IsType(base::Value::TYPE_DICTIONARY)) << name_;
-    value_as_dict.reset(static_cast<base::DictionaryValue*>(value.release()));
+    value_as_dict = base::DictionaryValue::From(value.Pass());
   } else {
     // There was some error loading the features file.
     // http://crbug.com/176381
     value_as_dict.reset(new base::DictionaryValue());
   }
 
   // Ensure there are no key collisions.
   for (base::DictionaryValue::Iterator iter(*value_as_dict); !iter.IsAtEnd();
        iter.Advance()) {
     if (dictionary_.GetWithoutPathExpansion(iter.key(), NULL))
       LOG(FATAL) << "Key " << iter.key() << " is defined in " << name_
                  << " JSON feature files more than once.";
   }
 
   // Merge.
   dictionary_.MergeDictionary(value_as_dict.get());
 }
 
 }  // namespace extensions