[Payments] Added region load failure tolerance and tests to PR editor.

chrome/browser/ui/views/payments/validating_textfield_unittest.cc

Index: chrome/browser/ui/views/payments/validating_textfield_unittest.cc
diff --git a/chrome/browser/ui/views/payments/validating_textfield_unittest.cc b/chrome/browser/ui/views/payments/validating_textfield_unittest.cc
index faa4768fe0efb2e32b95ed121f8059c0ba92309b..6260c40b5280657f814f8db6b94791d8a248e6d9 100644
--- a/chrome/browser/ui/views/payments/validating_textfield_unittest.cc
+++ b/chrome/browser/ui/views/payments/validating_textfield_unittest.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/ui/views/payments/validating_textfield.h"
 
 #include <memory>
+#include <utility>
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
@@ -32,6 +33,7 @@ class ValidatingTextfieldTest : public testing::Test {
       return textfield->text().size() <= 5u;
     }
     bool ValidateCombobox(views::Combobox* combobox) override { return true; }
+    void ComboboxModelChanged(views::Combobox* combobox) override {}
 
    private:
     DISALLOW_COPY_AND_ASSIGN(TestValidationDelegate);