Remove base::Value::CreateNullValue

net/test/spawned_test_server/remote_test_server.cc

Index: net/test/spawned_test_server/remote_test_server.cc
diff --git a/net/test/spawned_test_server/remote_test_server.cc b/net/test/spawned_test_server/remote_test_server.cc
index 17dc21eba2b5c98a0e74464bc260a0e17a4cd86f..90ec54e574db77663c260af4b9f5a96bd1c201c9 100644
--- a/net/test/spawned_test_server/remote_test_server.cc
+++ b/net/test/spawned_test_server/remote_test_server.cc
@@ -15,6 +15,7 @@
 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
+#include "base/memory/ptr_util.h"
 #include "base/path_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
@@ -127,7 +128,7 @@ bool RemoteTestServer::Start() {
   if (!GenerateArguments(&arguments_dict))
     return false;
 
-  arguments_dict.Set("on-remote-server", base::Value::CreateNullValue());
+  arguments_dict.Set("on-remote-server", base::MakeUnique<base::Value>());
 
   // Append the 'server-type' argument which is used by spawner server to
   // pass right server type to Python test server.