Rewrite std::string("") to std::string(), Linux edition.

chrome/browser/search_engines/template_url_prepopulate_data_unittest.cc

Index: chrome/browser/search_engines/template_url_prepopulate_data_unittest.cc
diff --git a/chrome/browser/search_engines/template_url_prepopulate_data_unittest.cc b/chrome/browser/search_engines/template_url_prepopulate_data_unittest.cc
index 3237137d2b2318262381b156321384b542123d7b..aa4799202bf417072d53b75cd248a3b7e0887692 100644
--- a/chrome/browser/search_engines/template_url_prepopulate_data_unittest.cc
+++ b/chrome/browser/search_engines/template_url_prepopulate_data_unittest.cc
@@ -167,7 +167,7 @@ TEST(TemplateURLPrepopulateDataTest, ProvidersFromPrefs) {
   entry->SetInteger("id", 1002);
   entry->SetString("name", "bar");
   entry->SetString("keyword", "bark");
-  entry->SetString("encoding", "");
+  entry->SetString("encoding", std::string());
   overrides->Append(entry->DeepCopy());
   entry->SetInteger("id", 1003);
   entry->SetString("name", "baz");