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

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 aaa2a61d92c4277119af947f899b5edf6280640e..f9e375011a77aad6343534da4da05f8688f7175b 100644
--- a/chrome/browser/ui/views/payments/payment_sheet_view_controller.cc
+++ b/chrome/browser/ui/views/payments/payment_sheet_view_controller.cc
@@ -171,7 +171,9 @@ PaymentSheetViewController::PaymentSheetViewController(
   request->AddObserver(this);
 }
 
-PaymentSheetViewController::~PaymentSheetViewController() {}
+PaymentSheetViewController::~PaymentSheetViewController() {
+  request()->RemoveObserver(this);
+}
 
 std::unique_ptr<views::View> PaymentSheetViewController::CreateView() {
   std::unique_ptr<views::View> content_view = base::MakeUnique<views::View>();