media: Add MediaDrmStorage

media/mojo/interfaces/media_drm_storage.mojom

+// 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.
+
+module media.mojom;
+
+import "url/mojo/origin.mojom";
+
+struct SessionData {
+  array<uint8> key_set_id;
+  string mime_type;
+};
+
+// Allows MediaDrmBridge to store and retrieve persistent data. This is needed
+// for features like per-origin provisioning and persistent license support.
+interface MediaDrmStorage {
+  // Initializes |this| to be bound to the |origin|. This should not modify
+  // anything in the storage.
+  Initialize(url.mojom.Origin origin);
+
+  // Saves |origin| in the storage after MediaDrm is provisioned for |origin|.
+  OnProvisioned() => (bool success);
+
+  // Saves persistent session data for |session_id|.
+  SavePersistentSession(
+    string session_id, SessionData session_data) => (bool success);
+
+  // Loads persistent session data for |session_id|.
+  // Upon failure, null |session_data| will be returned.
+  LoadPersistentSession(string session_id) => (SessionData? session_data);
+
+  // Removes the persistent session data for |session_id|.
+  RemovePersistentSession(string session_id) => (bool success);
+};