[Payments] Add the pay button, and control its enabled state

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

 // 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.
 
 #include "chrome/browser/ui/views/payments/payment_method_view_controller.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/memory/ptr_util.h"
@@ skipping 116 matching lines @@
 
     return std::move(row);
   }
 
   void SelectedStateChanged() override {
     // This could be called before CreateItemView, so before |checkmark_| is
     // instantiated.
     if (checkmark_)
       checkmark_->SetVisible(selected());
 
-    request()->set_selected_credit_card(card_);
+    request()->SetSelectedCreditCard(card_);
   }
 
   // views::ButtonListener:
   void ButtonPressed(views::Button* sender, const ui::Event& event) override {
     if (IsComplete()) {
       list()->SelectItem(this);
     } else {
       // TODO(anthonyvd): Display the editor, pre-populated with the data that
       // already exists in |card|.
     }
@@ skipping 71 matching lines @@
         PaymentMethodViewControllerTags::ADD_CREDIT_CARD_BUTTON):
       dialog()->ShowCreditCardEditor();
       break;
     default:
       PaymentRequestSheetController::ButtonPressed(sender, event);
       break;
   }
 }
 
 }  // namespace payments