Cleanup return values in autofill

components/autofill/core/browser/autofill_country.h

Index: components/autofill/core/browser/autofill_country.h
diff --git a/components/autofill/core/browser/autofill_country.h b/components/autofill/core/browser/autofill_country.h
index 17bb74c49f6ac25b6da886129f9fa603b825300f..7b2414f232b6b5284092146217a0ea7f2fa53982 100644
--- a/components/autofill/core/browser/autofill_country.h
+++ b/components/autofill/core/browser/autofill_country.h
@@ -61,10 +61,10 @@ class AutofillCountry {
   static const std::string GetCountryCode(const base::string16& country,
                                           const std::string& locale);
 
-  const std::string country_code() const { return country_code_; }
-  const base::string16 name() const { return name_; }
-  const base::string16 postal_code_label() const { return postal_code_label_; }
-  const base::string16 state_label() const { return state_label_; }
+  const std::string& country_code() const { return country_code_; }
+  const base::string16& name() const { return name_; }
+  const base::string16& postal_code_label() const { return postal_code_label_; }
+  const base::string16& state_label() const { return state_label_; }
 
   // City is expected in a complete address for this country.
   bool requires_city() const {