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

chrome/browser/ui/webui/options/chromeos/display_options_handler.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 "chrome/browser/ui/webui/options/chromeos/display_options_handler.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <string>
@@ skipping 395 matching lines @@
     const base::ListValue* args) {
   const base::ListValue* layouts = nullptr;
   if (!args->GetList(0, &layouts))
     NOTREACHED();
   content::RecordAction(base::UserMetricsAction("Options_DisplayRearrange"));
 
   ash::DisplayManager* display_manager = GetDisplayManager();
   display::DisplayLayoutBuilder builder(
       display_manager->GetCurrentDisplayLayout());
   builder.ClearPlacements();
-  for (const base::Value* layout : *layouts) {
+  for (const auto& layout : *layouts) {
     const base::DictionaryValue* dictionary;
     if (!layout->GetAsDictionary(&dictionary)) {
       LOG(ERROR) << "Invalid layout dictionary: " << *dictionary;
       continue;
     }
 
     int64_t parent_id = GetDisplayIdFromDictionary(dictionary, "parentId");
     if (parent_id == display::Display::kInvalidDisplayID)
       continue;  // No placement for root (primary) display.
 
@@ skipping 128 matching lines @@
   bool enable = false;
   if (!args->GetBoolean(0, &enable))
     NOTREACHED();
 
   GetDisplayManager()->SetDefaultMultiDisplayModeForCurrentDisplays(
       enable ? ash::DisplayManager::UNIFIED : ash::DisplayManager::EXTENDED);
 }
 
 }  // namespace options
 }  // namespace chromeos