[Payments] Fix bug in shipping option selection.

chrome/browser/ui/views/payments/shipping_option_view_controller.h

Index: chrome/browser/ui/views/payments/shipping_option_view_controller.h
diff --git a/chrome/browser/ui/views/payments/shipping_option_view_controller.h b/chrome/browser/ui/views/payments/shipping_option_view_controller.h
index fd604d4e83323acf3dd53a2982df53337697caf9..e7338f1ced806dc01c664f1f20432d428ab9d986 100644
--- a/chrome/browser/ui/views/payments/shipping_option_view_controller.h
+++ b/chrome/browser/ui/views/payments/shipping_option_view_controller.h
@@ -8,19 +8,24 @@
 #include "base/macros.h"
 #include "chrome/browser/ui/views/payments/payment_request_item_list.h"
 #include "chrome/browser/ui/views/payments/payment_request_sheet_controller.h"
+#include "components/payments/content/payment_request_spec.h"
 
 namespace payments {
 
-class PaymentRequestSpec;
 class PaymentRequestState;
 
-class ShippingOptionViewController : public PaymentRequestSheetController {
+class ShippingOptionViewController : public PaymentRequestSheetController,
+                                     public PaymentRequestSpec::Observer {
  public:
   ShippingOptionViewController(PaymentRequestSpec* spec,
                                PaymentRequestState* state,
                                PaymentRequestDialogView* dialog);
   ~ShippingOptionViewController() override;
 
+  // PaymentRequestSpec::Observer:
+  void OnInvalidSpecProvided() override {}
+  void OnSpecUpdated() override;
+
  private:
   // PaymentRequestSheetController:
   base::string16 GetSheetTitle() override;