Use std::unique_ptr for base::DictionaryValue and base::ListValue's internal store.

chrome/browser/extensions/extension_override_apitest.cc

 // Copyright (c) 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 <stddef.h>
 
 #include "build/build_config.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_web_ui.h"
@@ skipping 21 matching lines @@
     // There should be no duplicate entries in the preferences.
     const base::DictionaryValue* overrides =
         browser()->profile()->GetPrefs()->GetDictionary(
             ExtensionWebUI::kExtensionURLOverrides);
 
     const base::ListValue* values = nullptr;
     if (!overrides->GetList("history", &values))
       return false;
 
     std::set<std::string> seen_overrides;
-    for (const base::Value* val : *values) {
+    for (const auto& val : *values) {
       const base::DictionaryValue* dict = nullptr;
       std::string entry;
       if (!val->GetAsDictionary(&dict) || !dict->GetString("entry", &entry) ||
           seen_overrides.count(entry) != 0)
         return false;
       seen_overrides.insert(entry);
     }
 
     return true;
   }
@@ skipping 195 matching lines @@
   }
 
   ASSERT_FALSE(CheckHistoryOverridesContainsNoDupes());
 
   ExtensionWebUI::InitializeChromeURLOverrides(profile());
 
   ASSERT_TRUE(CheckHistoryOverridesContainsNoDupes());
 }
 
 }  // namespace extensions