Fix memory leak in PrefMetricsService

base/values.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 "base/values.h"
 
 #include <string.h>
 
 #include <algorithm>
 #include <ostream>
@@ skipping 737 matching lines @@
 
   Value* entry = entry_iterator->second;
   if (out_value)
     out_value->reset(entry);
   else
     delete entry;
   dictionary_.erase(entry_iterator);
   return true;
 }
 
-DictionaryValue* DictionaryValue::DeepCopyWithoutEmptyChildren() {
+DictionaryValue* DictionaryValue::DeepCopyWithoutEmptyChildren() const {
   Value* copy = CopyWithoutEmptyChildren(this);
   return copy ? static_cast<DictionaryValue*>(copy) : new DictionaryValue;
 }
 
 void DictionaryValue::MergeDictionary(const DictionaryValue* dictionary) {
   for (DictionaryValue::Iterator it(*dictionary); !it.IsAtEnd(); it.Advance()) {
     const Value* merge_value = &it.value();
     // Check whether we have to merge dictionaries.
     if (merge_value->IsType(Value::TYPE_DICTIONARY)) {
       DictionaryValue* sub_dict;
@@ skipping 344 matching lines @@
 
 std::ostream& operator<<(std::ostream& out, const Value& value) {
   std::string json;
   JSONWriter::WriteWithOptions(&value,
                                JSONWriter::OPTIONS_PRETTY_PRINT,
                                &json);
   return out << json;
 }
 
 }  // namespace base