[Payments] Add a Pay button in the Order summary screen

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

Index: chrome/browser/ui/views/payments/order_summary_view_controller.cc
diff --git a/chrome/browser/ui/views/payments/order_summary_view_controller.cc b/chrome/browser/ui/views/payments/order_summary_view_controller.cc
index 3589cc32eaae80b8213377530358903814bd3463..c2dc0896baaa3e69459de1206aff58c5e08617f5 100644
--- a/chrome/browser/ui/views/payments/order_summary_view_controller.cc
+++ b/chrome/browser/ui/views/payments/order_summary_view_controller.cc
@@ -15,12 +15,12 @@
 #include "chrome/browser/ui/views/payments/payment_request_dialog_view_ids.h"
 #include "chrome/browser/ui/views/payments/payment_request_views_util.h"
 #include "chrome/grit/generated_resources.h"
-#include "components/payments/content/payment_request.h"
 #include "components/payments/core/currency_formatter.h"
 #include "components/strings/grit/components_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/font.h"
 #include "ui/views/border.h"
+#include "ui/views/controls/button/md_text_button.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/controls/styled_label.h"
 #include "ui/views/layout/box_layout.h"
@@ -84,9 +84,13 @@ std::unique_ptr<views::View> CreateLineItemView(const base::string16& label,
 OrderSummaryViewController::OrderSummaryViewController(
     PaymentRequest* request,
     PaymentRequestDialogView* dialog)
-    : PaymentRequestSheetController(request, dialog) {}
+    : PaymentRequestSheetController(request, dialog), pay_button_(nullptr) {
+  request->AddObserver(this);
+}
 
-OrderSummaryViewController::~OrderSummaryViewController() {}
+OrderSummaryViewController::~OrderSummaryViewController() {
+  request()->RemoveObserver(this);
+}
 
 std::unique_ptr<views::View> OrderSummaryViewController::CreateView() {
   std::unique_ptr<views::View> content_view = base::MakeUnique<views::View>();
@@ -139,4 +143,24 @@ std::unique_ptr<views::View> OrderSummaryViewController::CreateView() {
       std::move(content_view));
 }
 
+std::unique_ptr<views::Button>
+OrderSummaryViewController::CreatePrimaryButton() {
+  std::unique_ptr<views::Button> button(
+      views::MdTextButton::CreateSecondaryUiBlueButton(
+          this, l10n_util::GetStringUTF16(IDS_PAYMENTS_PAY_BUTTON)));
+  button->set_tag(static_cast<int>(PaymentRequestCommonTags::PAY_BUTTON_TAG));
+  button->set_id(static_cast<int>(DialogViewID::PAY_BUTTON));
+  pay_button_ = button.get();
+  UpdatePayButtonState(request()->is_ready_to_pay());
+  return button;
+}
+
+void OrderSummaryViewController::OnSelectedInformationChanged() {
+  UpdatePayButtonState(request()->is_ready_to_pay());
+}
+
+void OrderSummaryViewController::UpdatePayButtonState(bool enabled) {
+  pay_button_->SetEnabled(enabled);
+}
+
 }  // namespace payments