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

base/trace_event/trace_event_argument.cc

Index: base/trace_event/trace_event_argument.cc
diff --git a/base/trace_event/trace_event_argument.cc b/base/trace_event/trace_event_argument.cc
index 8babf3b47faa882a89893479c8594f86e66e518b..539937e14e1687dc430576112fe8ce00a75c310a 100644
--- a/base/trace_event/trace_event_argument.cc
+++ b/base/trace_event/trace_event_argument.cc
@@ -288,7 +288,7 @@ void TracedValue::SetBaseValueWithCopiedName(base::StringPiece name,
       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;
@@ -342,7 +342,7 @@ void TracedValue::AppendBaseValue(const base::Value& value) {
       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;