[Payments] Improve the closing of the PR dialog.

chrome/browser/payments/chrome_payment_request_delegate.h

Index: chrome/browser/payments/chrome_payment_request_delegate.h
diff --git a/chrome/browser/payments/chrome_payment_request_delegate.h b/chrome/browser/payments/chrome_payment_request_delegate.h
index 4f54fb5f47d6fc067ede1df71e7f36927908744f..25fb7404c3e3caebfe250f1e410d8188f60844d1 100644
--- a/chrome/browser/payments/chrome_payment_request_delegate.h
+++ b/chrome/browser/payments/chrome_payment_request_delegate.h
@@ -15,15 +15,23 @@ class WebContents;
 namespace payments {
 
 class PaymentRequest;
+class PaymentRequestDialog;
 
 class ChromePaymentRequestDelegate : public PaymentRequestDelegate {
  public:
   explicit ChromePaymentRequestDelegate(content::WebContents* web_contents);
   ~ChromePaymentRequestDelegate() override {}
 
-  void ShowPaymentRequestDialog(PaymentRequest* request) override;
+  void ShowDialog(PaymentRequest* request) override;
+  void CloseDialog() override;
   autofill::PersonalDataManager* GetPersonalDataManager() override;
 
+ protected:
+  // Reference to the dialog so that we can satisfy calls to CloseDialog(). This
+  // reference is invalid once CloseDialog() has been called on it, because the
+  // dialog will be destroyed. Protected for testing.
+  PaymentRequestDialog* dialog_;
+
  private:
   // Not owned but outlives the PaymentRequest object that owns this.
   content::WebContents* web_contents_;