base: Add three helper functions to Values API.

ipc/ipc_message_utils.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 "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 133 matching lines @@
     LOG(WARNING) << "Max recursion depth hit in ReadValue.";
     return false;
   }
 
   int type;
   if (!ReadParam(m, iter, &type))
     return false;
 
   switch (type) {
     case Value::TYPE_NULL:
-    *value = Value::CreateNullValue();
+    *value = base::NullValue();
     break;
     case Value::TYPE_BOOLEAN: {
       bool val;
       if (!ReadParam(m, iter, &val))
         return false;
       *value = Value::CreateBooleanValue(val);
       break;
     }
     case Value::TYPE_INTEGER: {
       int val;
@@ skipping 304 matching lines @@
       ReadParam(m, iter, &r->flags) &&
       ReadParam(m, iter, &r->sent) &&
       ReadParam(m, iter, &r->receive) &&
       ReadParam(m, iter, &r->dispatch) &&
       ReadParam(m, iter, &r->params);
   r->type = static_cast<uint16>(type);
   return result;
 }
 
 }  // namespace IPC