media: Use new wrapper types for media mojo interfaces

media/mojo/interfaces/content_decryption_module.mojom

 // Copyright 2014 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 "media/mojo/interfaces/decryptor.mojom";
 import "url/mojo/url.mojom";
 
 // Transport layer of media::MediaKeys::Exception (see media/base/media_keys.h).
@@ skipping 30 matching lines @@
 
 // Transport layer of media::CdmPromise (see media/base/cdm_promise.h).
 // - When |success| is true, the promise is resolved and all other fields should
 //   be ignored.
 // - When |success| is false, the promise is rejected with |exception|,
 //   |system_code| and |error_message|.
 struct CdmPromiseResult {
   bool success;
   CdmException exception;
   uint32 system_code;
-  string? error_message;
+  string error_message;
 };
 
 // Transport layer of media::CdmKeyInformation (see
 // media/base/cdm_key_information.h). It is used to specify a key_id and it's
 // associated status.
 struct CdmKeyInformation {
   array<uint8> key_id;
   CdmKeyStatus status;
   uint32 system_code;
 };
@@ skipping 34 matching lines @@
   Initialize(string key_system, string security_origin, CdmConfig cdm_config)
       => (CdmPromiseResult result, int32 cdm_id, Decryptor? decryptor);
 
   // Provides a server certificate to be used to encrypt messages to the
   // license server.
   SetServerCertificate(array<uint8> certificate_data)
       => (CdmPromiseResult result);
 
   // Creates a session with the |init_data_type|, |init_data| and |session_type|
   // provided. If |result.success| is false, the output |session_id| will be
-  // null.
+  // empty.
   CreateSessionAndGenerateRequest(SessionType session_type,
                                   InitDataType init_data_type,
                                   array<uint8> init_data)
-      => (CdmPromiseResult result, string? session_id);
+      => (CdmPromiseResult result, string session_id);
 
   // Loads the session associated with |session_id| and |session_type|.
   // Combinations of |result.success| and |session_id| means:
-  //   (true, non-null) : Session successfully loaded.
-  //   (true, null) : Session not found.
-  //   (false, non-null): N/A; this combination is not allowed.
-  //   (false, null) : Unexpected error. See other fields in |result|.
+  //   (true, non-empty) : Session successfully loaded.
+  //   (true, empty) : Session not found.
+  //   (false, non-empty): N/A; this combination is not allowed.
+  //   (false, empty) : Unexpected error. See other fields in |result|.
   LoadSession(SessionType session_type, string session_id)
-      => (CdmPromiseResult result, string? session_id);
+      => (CdmPromiseResult result, string session_id);
 
   // Updates a session specified by |session_id| with |response|.
   UpdateSession(string session_id, array<uint8> response)
       => (CdmPromiseResult result);
 
   // Closes the session specified by |session_id|.
   CloseSession(string session_id) => (CdmPromiseResult result);
 
   // Removes stored session data associated with the active session specified by
   // |session_id|.
   RemoveSession(string session_id) => (CdmPromiseResult result);
 };
 
 // Session callbacks. See media/base/media_keys.h for details.
 interface ContentDecryptionModuleClient {
   OnSessionMessage(string session_id, CdmMessageType message_type,
                    array<uint8> message);
 
   OnSessionClosed(string session_id);
 
   OnSessionKeysChange(string session_id, bool has_additional_usable_key,
-                      array<CdmKeyInformation> key_information);
+                      array<CdmKeyInformation> keys_info);
 
   // Provide session expiration update for |session_id|.
   // |new_expiry_time_sec| is the number of seconds since epoch (Jan 1, 1970).
   OnSessionExpirationUpdate(string session_id, double new_expiry_time_sec);
 };