Rewrite scoped_ptr<T>(NULL) to use the default ctor in chrome/.

chrome/test/chromedriver/chrome/performance_logger_unittest.cc

Index: chrome/test/chromedriver/chrome/performance_logger_unittest.cc
diff --git a/chrome/test/chromedriver/chrome/performance_logger_unittest.cc b/chrome/test/chromedriver/chrome/performance_logger_unittest.cc
index 8f655b0395d9a614693010a013102369da7979c2..a3a36277a853ab87f8432171a6ce9ded5173e291 100644
--- a/chrome/test/chromedriver/chrome/performance_logger_unittest.cc
+++ b/chrome/test/chromedriver/chrome/performance_logger_unittest.cc
@@ -103,13 +103,13 @@ scoped_ptr<DictionaryValue> ParseDictionary(const std::string& json) {
     SCOPED_TRACE(json.c_str());
     SCOPED_TRACE(error.c_str());
     ADD_FAILURE();
-    return scoped_ptr<DictionaryValue>(NULL);
+    return scoped_ptr<DictionaryValue>();
   }
   DictionaryValue* dict = NULL;
   if (!value->GetAsDictionary(&dict)) {
     SCOPED_TRACE("JSON object is not a dictionary");
     ADD_FAILURE();
-    return scoped_ptr<DictionaryValue>(NULL);
+    return scoped_ptr<DictionaryValue>();
   }
   return scoped_ptr<DictionaryValue>(dict->DeepCopy());
 }