PaymentApp: Add PaymentAppProvider class.

content/browser/payments/payment_app_context_impl.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 CONTENT_BROWSER_PAYMENTS_PAYMENT_APP_CONTEXT_IMPL_H_
 #define CONTENT_BROWSER_PAYMENTS_PAYMENT_APP_CONTEXT_IMPL_H_
 
 #include <map>
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "components/payments/payment_app.mojom.h"
 #include "content/browser/payments/payment_app_database.h"
 #include "content/common/content_export.h"
-#include "content/public/browser/payment_app_context.h"
 
 namespace content {
 
 class PaymentAppDatabase;
 class PaymentAppManager;
 class ServiceWorkerContextWrapper;
 
 // One instance of this exists per StoragePartition, and services multiple child
 // processes/origins. Most logic is delegated to the owned PaymentAppDatabase
 // instance, which is only accessed on the IO thread.
 //
 // This class is created/destructed by StoragePartitionImpl on UI thread.
 // However, the PaymentAppDatabase that this class has internally should work on
 // IO thread. So, this class has Init() and Shutdown() methods in addition to
 // constructor and destructor. They should be called explicitly when creating
 // and destroying StoragePartitionImpl.
 //
 // Expected order of lifetime calls:
 //   1) Constructor
 //   2) Init()
 //   3) Can now call other public methods in this class in any order.
 //     - Can call CreatePaymentAppManager() on UI thread.
 //     - Can call GetAllManifests() on UI thread.
 //     - Can call PaymentAppManagerHadConnectionError() on IO thread.
 //     - Can call payment_app_database() on IO thread.
 //   4) Shutdown()
 //   5) Destructor
 class CONTENT_EXPORT PaymentAppContextImpl
-    : public base::RefCountedThreadSafe<PaymentAppContextImpl>,
-      NON_EXPORTED_BASE(public PaymentAppContext) {
+    : public base::RefCountedThreadSafe<PaymentAppContextImpl> {
  public:
   PaymentAppContextImpl();
 
   // Init and Shutdown are for use on the UI thread when the
   // StoragePartition is being setup and torn down.
   void Init(scoped_refptr<ServiceWorkerContextWrapper> service_worker_context);
 
   // Shutdown must be called before deleting this. Call on the UI thread.
   void Shutdown();
 
   // Create a PaymentAppManager that is owned by this. Call on the UI
   // thread.
   void CreatePaymentAppManager(
       mojo::InterfaceRequest<payments::mojom::PaymentAppManager> request);
 
   // Called by PaymentAppManager objects so that they can
   // be deleted. Call on the IO thread.
   void PaymentAppManagerHadConnectionError(PaymentAppManager* service);
 
   // Should be accessed only on the IO thread.
   PaymentAppDatabase* payment_app_database() const;
 
-  // PaymentAppContext implementation:
-  // Should be accessed only on the UI thread.
-  void GetAllManifests(const GetAllManifestsCallback& callback) override;
-
  private:
   friend class PaymentAppContentUnitTestBase;
   friend class base::RefCountedThreadSafe<PaymentAppContextImpl>;
-  ~PaymentAppContextImpl() override;

[please use gerrit instead, 2017/01/04 16:55:43]

base::RefCountedThreadSafe has a destructor, so we should keep the override
keyword. Does the default destructor in the parent class prevent use from
overriding the parent destructor?

[zino, 2017/01/04 17:29:59]

Done.

[zino, 2017/01/05 00:08:04]

There was no virtual destructor in RefCountedThreadSafe class.
 -
https://cs.chromium.org/chromium/src/base/memory/ref_counted.h?q=RefCountedTh...

The class seems to use type traits with static_cast pattern instead of virtual
destructor.
 -
https://cs.chromium.org/chromium/src/base/memory/ref_counted.h?q=RefCountedTh...

So, I'll remove override keyword.

+  ~PaymentAppContextImpl();
 
   void CreatePaymentAppDatabaseOnIO(
       scoped_refptr<ServiceWorkerContextWrapper> service_worker_context);
 
   void CreatePaymentAppManagerOnIO(
       mojo::InterfaceRequest<payments::mojom::PaymentAppManager> request);
 
   void ShutdownOnIO();
   void DidShutdown();
 
-  void GetAllManifestsOnIO(const GetAllManifestsCallback& callback);
-  void DidGetAllManifestsOnIO(const GetAllManifestsCallback& callback,
-                              PaymentAppDatabase::Manifests manifests);
-
   // Only accessed on the IO thread.
   std::unique_ptr<PaymentAppDatabase> payment_app_database_;
 
   // The PaymentAppManagers are owned by this. They're either deleted during
   // ShutdownOnIO or when the channel is closed via
   // PaymentAppManagerHadConnectionError. Only accessed on the IO thread.
   std::map<PaymentAppManager*, std::unique_ptr<PaymentAppManager>>
       payment_app_managers_;
 
   // Only accessed on the UI thread.
   bool is_shutdown_;
 
   DISALLOW_COPY_AND_ASSIGN(PaymentAppContextImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_PAYMENTS_PAYMENT_APP_CONTEXT_IMPL_H_