media: Use new wrapper types for media mojo interfaces

media/base/media_keys.h

 // Copyright 2013 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 MEDIA_BASE_MEDIA_KEYS_H_
 #define MEDIA_BASE_MEDIA_KEYS_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 103 matching lines @@
   //    which must be AFTER the |promise| is resolved. Otherwise, the session ID
   //    in the callback will not be recognized.
   // 3. UpdateSession(), CloseSession() and RemoveSession() should only be
   //    called after the |promise| is resolved.
   virtual void CreateSessionAndGenerateRequest(
       SessionType session_type,
       EmeInitDataType init_data_type,
       const std::vector<uint8_t>& init_data,
       std::unique_ptr<NewSessionCdmPromise> promise) = 0;
 
-  // Loads a session with the |session_id| provided.
+  // Loads a session with the |session_id| provided. Resolves the |promise| with
+  // |session_id| if the session is successfully loaded. Resolves the |promise|
+  // with an empty session ID if the session cannot be found. Rejects the
+  // |promise| if session loading is not supported, or other unexpected failure
+  // happened.
   // Note: UpdateSession(), CloseSession() and RemoveSession() should only be
   //       called after the |promise| is resolved.
   virtual void LoadSession(SessionType session_type,
                            const std::string& session_id,
                            std::unique_ptr<NewSessionCdmPromise> promise) = 0;
 
   // Updates a session specified by |session_id| with |response|.
   virtual void UpdateSession(const std::string& session_id,
                              const std::vector<uint8_t>& response,
                              std::unique_ptr<SimpleCdmPromise> promise) = 0;
@@ skipping 63 matching lines @@
 
 // Called when the CDM changes the expiration time of a session.
 // See http://w3c.github.io/encrypted-media/#update-expiration
 typedef base::Callback<void(const std::string& session_id,
                             const base::Time& new_expiry_time)>
     SessionExpirationUpdateCB;
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_MEDIA_KEYS_H_