Correct const accessors in base/values.(h|cc), Part II (ListValue)

ipc/ipc_message_utils.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 "ipc/ipc_message_utils.h"
 
 #include "base/file_path.h"
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/nullable_string16.h"
@@ skipping 99 matching lines @@
         } else {
           NOTREACHED() << "DictionaryValue iterators are filthy liars.";
         }
       }
       break;
     }
     case Value::TYPE_LIST: {
       const ListValue* list = static_cast<const ListValue*>(value);
       WriteParam(m, static_cast<int>(list->GetSize()));
       for (size_t i = 0; i < list->GetSize(); ++i) {
-        Value* subval;
+        const Value* subval;
         if (list->Get(i, &subval)) {
           WriteValue(m, subval, recursion + 1);
         } else {
           NOTREACHED() << "ListValue::GetSize is a filthy liar.";
         }
       }
       break;
     }
   }
 }
@@ skipping 709 matching lines @@
   return result;
 }
 
 void ParamTraits<MSG>::Log(const param_type& p, std::string* l) {
   l->append("<MSG>");
 }
 
 #endif  // OS_WIN
 
 }  // namespace IPC