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

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

Index: chrome/browser/ui/views/payments/payment_sheet_view_controller.cc
diff --git a/chrome/browser/ui/views/payments/payment_sheet_view_controller.cc b/chrome/browser/ui/views/payments/payment_sheet_view_controller.cc
index dfcf2a696a1f031781b80711c4e31c99344e6cf4..277d78110dce24533b42f9599debd6accd676249 100644
--- a/chrome/browser/ui/views/payments/payment_sheet_view_controller.cc
+++ b/chrome/browser/ui/views/payments/payment_sheet_view_controller.cc
@@ -32,7 +32,6 @@
 #include "ui/gfx/font.h"
 #include "ui/gfx/paint_vector_icon.h"
 #include "ui/gfx/range/range.h"
-#include "ui/views/controls/button/label_button.h"
 #include "ui/views/controls/button/md_text_button.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/controls/label.h"
@@ -54,6 +53,7 @@ enum class PaymentSheetViewControllerTags {
   SHOW_SHIPPING_BUTTON,
   SHOW_PAYMENT_METHOD_BUTTON,
   SHOW_CONTACT_INFO_BUTTON,
+  PAY_BUTTON
 };
 
 int ComputeWidestNameColumnViewWidth() {
@@ -167,6 +167,7 @@ PaymentSheetViewController::PaymentSheetViewController(
     PaymentRequest* request,
     PaymentRequestDialogView* dialog)
     : PaymentRequestSheetController(request, dialog),
+      pay_button_(nullptr),
       widest_name_column_view_width_(ComputeWidestNameColumnViewWidth()) {}
 
 PaymentSheetViewController::~PaymentSheetViewController() {}
@@ -197,6 +198,18 @@ std::unique_ptr<views::View> PaymentSheetViewController::CreateView() {
       std::move(content_view));
 }
 
+std::unique_ptr<views::Button>
+PaymentSheetViewController::CreatePrimaryButton() {
+  std::unique_ptr<views::Button> button(
+      views::MdTextButton::CreateSecondaryUiBlueButton(
+          this, l10n_util::GetStringUTF16(IDS_PAYMENTS_PAY_BUTTON)));
+  button->set_tag(static_cast<int>(PaymentSheetViewControllerTags::PAY_BUTTON));
+  button->set_id(static_cast<int>(DialogViewID::PAYMENT_SHEET_PAY_BUTTON));
+  pay_button_ = button.get();
+  UpdatePayButtonState(request()->is_ready_to_pay());
+  return button;
+}
+
 void PaymentSheetViewController::ButtonPressed(
     views::Button* sender, const ui::Event& event) {
   switch (sender->tag()) {
@@ -219,12 +232,20 @@ void PaymentSheetViewController::ButtonPressed(
       // TODO(tmartino): Transition to contact info page once it exists.
       break;
 
+    case static_cast<int>(PaymentSheetViewControllerTags::PAY_BUTTON):
+      request()->Pay();
+      break;
+
     default:
       PaymentRequestSheetController::ButtonPressed(sender, event);
       break;
   }
 }
 
+void PaymentSheetViewController::UpdatePayButtonState(bool enabled) {
+  pay_button_->SetEnabled(enabled);
+}
+
 std::unique_ptr<views::View>
 PaymentSheetViewController::CreateOrderSummarySectionContent() {
   CurrencyFormatter* formatter = request()->GetOrCreateCurrencyFormatter(