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

chrome/browser/ui/views/payments/payment_request_sheet_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_request_sheet_controller.h"
 
 #include "chrome/browser/ui/views/payments/payment_request_dialog_view.h"
 #include "chrome/browser/ui/views/payments/payment_request_views_util.h"
+#include "components/payments/content/payment_request.h"
 #include "components/strings/grit/components_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/views/background.h"
 #include "ui/views/controls/button/md_text_button.h"
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/layout/grid_layout.h"
 
 namespace payments {
 
 PaymentRequestSheetController::PaymentRequestSheetController(
@@ skipping 13 matching lines @@
 
 void PaymentRequestSheetController::ButtonPressed(
     views::Button* sender, const ui::Event& event) {
   switch (static_cast<PaymentRequestCommonTags>(sender->tag())) {
     case PaymentRequestCommonTags::CLOSE_BUTTON_TAG:
       dialog()->CloseDialog();
       break;
     case PaymentRequestCommonTags::BACK_BUTTON_TAG:
       dialog()->GoBack();
       break;
+    case PaymentRequestCommonTags::PAY_BUTTON_TAG:
+      request()->Pay();
+      break;
     case PaymentRequestCommonTags::PAYMENT_REQUEST_COMMON_TAG_MAX:
       NOTREACHED();
       break;
   }
 }
 
 std::unique_ptr<views::View> PaymentRequestSheetController::CreatePaymentView(
     std::unique_ptr<views::View> header_view,
     std::unique_ptr<views::View> content_view) {
   std::unique_ptr<views::View> view = base::MakeUnique<views::View>();
@@ skipping 69 matching lines @@
       this, l10n_util::GetStringUTF16(IDS_CANCEL));
   button->set_tag(static_cast<int>(PaymentRequestCommonTags::CLOSE_BUTTON_TAG));
   trailing_buttons_container->AddChildView(button);
 
   layout->AddView(trailing_buttons_container.release());
 
   return container;
 }
 
 }  // namespace payments