Remove raw DictionaryValue::Set in //chrome

chrome/browser/prerender/prerender_history.cc

 // Copyright (c) 2011 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/prerender/prerender_history.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/logging.h"
+#include "base/memory/ptr_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/values.h"
 
 namespace prerender {
 
 PrerenderHistory::PrerenderHistory(size_t max_items)
     : max_items_(max_items) {
   DCHECK(max_items > 0);
 }
 
 PrerenderHistory::~PrerenderHistory() {
 }
 
 void PrerenderHistory::AddEntry(const Entry& entry) {
   DCHECK(CalledOnValidThread());
   while (entries_.size() >= max_items_)
     entries_.pop_front();
   entries_.push_back(entry);
 }
 
 void PrerenderHistory::Clear() {
   entries_.clear();
 }
 
-base::Value* PrerenderHistory::GetEntriesAsValue() const {
-  base::ListValue* return_list = new base::ListValue();
+std::unique_ptr<base::Value> PrerenderHistory::GetEntriesAsValue() const {
+  auto return_list = base::MakeUnique<base::ListValue>();
   // Javascript needs times in terms of milliseconds since Jan 1, 1970.
   base::Time epoch_start = base::Time::UnixEpoch();
   for (std::list<Entry>::const_reverse_iterator it = entries_.rbegin();
        it != entries_.rend();
        ++it) {
     const Entry& entry = *it;
-    std::unique_ptr<base::DictionaryValue> entry_dict(
-        new base::DictionaryValue());
+    auto entry_dict = base::MakeUnique<base::DictionaryValue>();
     entry_dict->SetString("url", entry.url.spec());
     entry_dict->SetString("final_status",
                           NameFromFinalStatus(entry.final_status));
     entry_dict->SetString("origin", NameFromOrigin(entry.origin));
     // Use a string to prevent overflow, as Values don't support 64-bit
     // integers.
     entry_dict->SetString(
         "end_time",
         base::Int64ToString((entry.end_time - epoch_start).InMilliseconds()));
     return_list->Append(std::move(entry_dict));
   }
-  return return_list;
+  return std::move(return_list);
 }
 
 }  // namespace prerender