[Payment Request] Change the lifetime management of PaymentRequestImpl

components/payments/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 <unordered_map>
+
+#include "components/payments/payment_request.h"
+#include "components/payments/payment_request.mojom.h"
+#include "content/public/browser/web_contents_user_data.h"
+#include "mojo/public/cpp/bindings/binding.h"
+
+namespace payments {
+
+class PaymentRequestDelegate;
+
+// This class owns the PaymentRequest associated with a given WebContents.
+//
+// Responsible for creating PaymentRequest's and retaining ownership. No request
+// pointers are currently available because the request manages its interactions
+// with UI and renderer. The PaymentRequest may call DestroyRequest() to signal
+// it is ready to die. Otherwise it gets destroyed when the WebContents (thus
+// this class) goes away.
+class PaymentRequestWebContentsManager
+    : public content::WebContentsUserData<PaymentRequestWebContentsManager> {
+ public:
+  ~PaymentRequestWebContentsManager() override;
+
+  // Retrieves the instance of PaymentRequestWebContentsManager that was
+  // attached to the specified WebContents.  If no instance was attached,
+  // creates one, and attaches it to the specified WebContents.
+  static PaymentRequestWebContentsManager* GetOrCreateForWebContents(
+      content::WebContents* web_contents);
+
+  // 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);
+
+  // Destroys the given |request|.
+  void DestroyRequest(PaymentRequest* request);
+
+ private:
+  explicit PaymentRequestWebContentsManager(content::WebContents* web_contents);
+  friend class content::WebContentsUserData<PaymentRequestWebContentsManager>;
+  friend class PaymentRequestWebContentsManagerBrowserTest;
+
+  // 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_;
+};
+
+}  // namespace payments
+
+#endif  // COMPONENTS_PAYMENTS_PAYMENT_REQUEST_IMPL_H_