Verify behavior of PaymentRequest.show() method, part 1.

components/payments/content/payment_request_web_contents_manager.h

 // Copyright 2017 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 COMPONENTS_PAYMENTS_PAYMENT_REQUEST_WEB_CONTENTS_MANAGER_H_
 #define COMPONENTS_PAYMENTS_PAYMENT_REQUEST_WEB_CONTENTS_MANAGER_H_
 
+#include <map>
 #include <memory>
-#include <unordered_map>
 
 #include "base/macros.h"
 #include "components/payments/content/payment_request.h"
 #include "components/payments/mojom/payment_request.mojom.h"
 #include "content/public/browser/web_contents_user_data.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace content {
 class WebContents;
 }
@@ skipping 23 matching lines @@
   // Creates the PaymentRequest that will interact with this |web_contents|.
   void CreatePaymentRequest(
       content::WebContents* web_contents,
       std::unique_ptr<PaymentRequestDelegate> delegate,
       mojo::InterfaceRequest<payments::mojom::PaymentRequest> request,
       PaymentRequest::ObserverForTest* observer_for_testing);
 
   // Destroys the given |request|.
   void DestroyRequest(PaymentRequest* request);
 
+  // Called when |request| has received the show() call. If the |request| can be
+  // shown, then returns true and assumes that |request| is now showing until
+  // DestroyRequest(|request|) is called with the same pointer. (Only one
+  // request at a time can be shown per tab.)
+  bool CanShow(PaymentRequest* request);
+
  private:
   explicit PaymentRequestWebContentsManager(content::WebContents* web_contents);
   friend class content::WebContentsUserData<PaymentRequestWebContentsManager>;
   friend class PaymentRequestBrowserTestBase;
 
   // Owns all the PaymentRequest for this WebContents. Since the
   // PaymentRequestWebContentsManager's lifetime is tied to the WebContents,
   // these requests only get destroyed when the WebContents goes away, or when
   // the requests themselves call DestroyRequest().
-  std::unordered_map<PaymentRequest*, std::unique_ptr<PaymentRequest>>
-      payment_requests_;
+  std::map<PaymentRequest*, std::unique_ptr<PaymentRequest>> payment_requests_;
+
+  // The currently displayed instance of PaymentRequest. Points to one of the
+  // elements in |payment_requests_|. Can be null.
+  PaymentRequest* showing_;
 
   DISALLOW_COPY_AND_ASSIGN(PaymentRequestWebContentsManager);
 };
 
 }  // namespace payments
 
 #endif  // COMPONENTS_PAYMENTS_PAYMENT_REQUEST_WEB_CONTENTS_MANAGER_H_