Remove base::Value::CreateNullValue

extensions/renderer/script_injection.cc

Index: extensions/renderer/script_injection.cc
diff --git a/extensions/renderer/script_injection.cc b/extensions/renderer/script_injection.cc
index cd7da1bbbf78a4db4c6db0f5bf6ff320242802f7..3e9942b635641c7fc0fdaa8b11afdd1b1848b810 100644
--- a/extensions/renderer/script_injection.cc
+++ b/extensions/renderer/script_injection.cc
@@ -9,6 +9,7 @@
 
 #include "base/lazy_instance.h"
 #include "base/macros.h"
+#include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/timer/elapsed_timer.h"
 #include "base/values.h"
@@ -358,7 +359,7 @@ void ScriptInjection::OnJsInjectionCompleted(
       execution_result_ = v8_converter->FromV8Value(results[0], context);
     }
     if (!execution_result_.get())
-      execution_result_ = base::Value::CreateNullValue();
+      execution_result_ = base::MakeUnique<base::Value>();
   }
   did_inject_js_ = true;