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

base/trace_event/trace_event_argument.cc

 // Copyright (c) 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 "base/trace_event/trace_event_argument.h"
 
 #include <stdint.h>
 
 #include <utility>
 
@@ skipping 270 matching lines @@
            it.Advance()) {
         SetBaseValueWithCopiedName(it.key(), it.value());
       }
       EndDictionary();
     } break;
 
     case base::Value::TYPE_LIST: {
       const ListValue* list_value;
       value.GetAsList(&list_value);
       BeginArrayWithCopiedName(name);
-      for (base::Value* base_value : *list_value)
+      for (const base::Value* base_value : *list_value)

[dcheng, 2016/05/20 19:49:47]

Because I changed const_iterator to return a const Value* rather than a Value*.
Dunno if this is useful or if I should just have it match
std::vector<>::const_iterator more closely.

         AppendBaseValue(*base_value);
       EndArray();
     } break;
   }
 }
 
 void TracedValue::AppendBaseValue(const base::Value& value) {
   DCHECK_CURRENT_CONTAINER_IS(kStackTypeArray);
   switch (value.GetType()) {
     case base::Value::TYPE_NULL:
@@ skipping 33 matching lines @@
            it.Advance()) {
         SetBaseValueWithCopiedName(it.key(), it.value());
       }
       EndDictionary();
     } break;
 
     case base::Value::TYPE_LIST: {
       const ListValue* list_value;
       value.GetAsList(&list_value);
       BeginArray();
-      for (base::Value* base_value : *list_value)
+      for (const base::Value* base_value : *list_value)
         AppendBaseValue(*base_value);
       EndArray();
     } break;
   }
 }
 
 std::unique_ptr<base::Value> TracedValue::ToBaseValue() const {
   std::unique_ptr<DictionaryValue> root(new DictionaryValue);
   DictionaryValue* cur_dict = root.get();
   ListValue* cur_list = nullptr;
@@ skipping 108 matching lines @@
     TraceEventMemoryOverhead* overhead) {
   overhead->Add("TracedValue",
                 /* allocated size */
                 pickle_.GetTotalAllocatedSize(),
                 /* resident size */
                 pickle_.size());
 }
 
 }  // namespace trace_event
 }  // namespace base