[Payments] Add error messages to credit card editor.

chrome/browser/ui/views/payments/payment_request_interactive_uitest_base.h

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_PAYMENTS_PAYMENT_REQUEST_INTERACTIVE_UITEST_BASE_H_
 #define CHROME_BROWSER_UI_VIEWS_PAYMENTS_PAYMENT_REQUEST_INTERACTIVE_UITEST_BASE_H_
 
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 83 matching lines @@
   // an invalid state.
   bool IsEditorTextfieldInvalid(autofill::ServerFieldType type);
   bool IsEditorComboboxInvalid(autofill::ServerFieldType type);
 
   // Sets proper animation delegates and waits for animation to finish.
   void WaitForAnimation();
 
   // Returns the text of the StyledLabel with the specific |view_id| that is a
   // child of the Payment Request dialog view.
   const base::string16& GetStyledLabelText(DialogViewID view_id);
+  // Returns the error label text associated with a given field |type|.
+  const base::string16& GetErrorLabelForType(autofill::ServerFieldType type);
 
   net::EmbeddedTestServer* https_server() { return https_server_.get(); }
 
   PaymentRequestDialogView* dialog_view() { return delegate_->dialog_view(); }
 
   // Various events that can be waited on by the DialogEventObserver.
   enum DialogEvent : int {
     DIALOG_OPENED,
     DIALOG_CLOSED,
     ORDER_SUMMARY_OPENED,
@@ skipping 44 matching lines @@
   std::unique_ptr<net::EmbeddedTestServer> https_server_;
   // Weak, owned by the PaymentRequest object.
   TestChromePaymentRequestDelegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(PaymentRequestInteractiveTestBase);
 };
 
 }  // namespace payments
 
 #endif  // CHROME_BROWSER_UI_VIEWS_PAYMENTS_PAYMENT_REQUEST_INTERACTIVE_UITEST_BASE_H_