[Payments] Change how the dialog gets destroyed.

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_PAYMENTS_PAYMENT_REQUEST_DIALOG_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_PAYMENTS_PAYMENT_REQUEST_DIALOG_VIEW_H_
 
 #include <map>
 #include <memory>
 
@@ skipping 96 matching lines @@
   void ShowCvcUnmaskPrompt(
       const autofill::CreditCard& credit_card,
       base::WeakPtr<autofill::payments::FullCardRequest::ResultDelegate>
           result_delegate,
       content::WebContents* web_contents) override;
 
   // Shows a full dialog spinner with the "processing" label that doesn't offer
   // a way of closing the dialog.
   void ShowProcessingSpinner();
 
-  ViewStack* view_stack_for_testing() { return &view_stack_; }
+  ViewStack* view_stack_for_testing() { return view_stack_.get(); }
 
  private:
   void ShowInitialPaymentSheet();
   void SetupSpinnerOverlay();
 
   // views::View
   gfx::Size GetPreferredSize() const override;
   void ViewHierarchyChanged(
       const ViewHierarchyChangedDetails& details) override;
 
   // Non-owned reference to the PaymentRequest that initiated this dialog. Since
   // the PaymentRequest object always outlives this one, the pointer should
   // always be valid even though there is no direct ownership relationship
   // between the two.
   PaymentRequest* request_;
   ControllerMap controller_map_;
-  ViewStack view_stack_;
+  std::unique_ptr<ViewStack> view_stack_;
 
   // A full dialog overlay that shows a spinner and the "processing" label. It's
   // hidden until ShowProcessingSpinner is called.
   views::View throbber_overlay_;
   views::Throbber throbber_;
 
   // May be null.
   ObserverForTest* observer_for_testing_;
 
   // Used when the dialog is being closed to avoid re-entrancy into the
   // controller_map_.
   bool being_closed_;
 
   DISALLOW_COPY_AND_ASSIGN(PaymentRequestDialogView);
 };
 
 }  // namespace payments
 
 #endif  // CHROME_BROWSER_UI_VIEWS_PAYMENTS_PAYMENT_REQUEST_DIALOG_VIEW_H_