media: Add MediaDrmStorage

components/cdm/browser/media_drm_storage_impl.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_CDM_BROWSER_MEDIA_DRM_STORAGE_IMPL_H_
+#define COMPONENTS_CDM_BROWSER_MEDIA_DRM_STORAGE_IMPL_H_
+
+#include "content/public/browser/render_frame_host.h"
+#include "media/mojo/interfaces/media_drm_storage.mojom.h"
+#include "url/origin.h"
+
+class PrefService;
+
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
+namespace cdm {
+
+// Implements media::mojom::MediaDrmStorage using PrefService.
+// This file is located under components/ so that it can be shared by multiple
+// content embedders (e.g. chrome and chromecast).
+class MediaDrmStorageImpl : public media::mojom::MediaDrmStorage {
+ public:
+  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
+
+  explicit MediaDrmStorageImpl(PrefService* pref_service);
+  ~MediaDrmStorageImpl() final;

[dcheng, 2017/03/29 01:17:23]

Alternatively, the entire class can be marked final:

class MediaDrmStorageImpl final : public ... {

[xhwang, 2017/03/29 20:47:25]

Done.

But then do I still need to mark each overridden method as final or override?
The style guide doesn't say anything about this...

+
+  // media::mojom::MediaDrmStorage implementation.
+  void Initialize(const url::Origin& origin) final;
+  void OnProvisioned(const OnProvisionedCallback& callback) final;
+  void SavePersistentSession(
+      const std::string& session_id,
+      const std::vector<uint8_t>& key_set_id,
+      const std::string& mime_type,
+      const SavePersistentSessionCallback& callback) final;
+  void LoadPersistentSession(
+      const std::string& session_id,
+      const LoadPersistentSessionCallback& callback) final;
+  void RemovePersistentSession(
+      const std::string& session_id,
+      const RemovePersistentSessionCallback& callback) final;
+
+ private:
+  PrefService* pref_service_;
+
+  // Store the origin in a string so it can be used as a key in the dictionary.
+  std::string origin_;
+
+  base::WeakPtrFactory<MediaDrmStorageImpl> weak_factory_;
+};
+
+}  // namespace cdm
+
+#endif  // COMPONENTS_CDM_BROWSER_MEDIA_DRM_STORAGE_IMPL_H_