media: Rename MediaKeys to ContentDecryptionModule

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>
-#include <string>
-#include <vector>
-
-#include "base/callback.h"
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_vector.h"
-#include "media/base/eme_constants.h"
-#include "media/base/media_export.h"
-#include "url/gurl.h"
-
-namespace base {
-class Time;
-}
-
-namespace media {
-
-class CdmContext;
-struct CdmKeyInformation;
-struct MediaKeysTraits;
-
-template <typename... T>
-class CdmPromiseTemplate;
-
-typedef CdmPromiseTemplate<std::string> NewSessionCdmPromise;
-typedef CdmPromiseTemplate<> SimpleCdmPromise;
-typedef ScopedVector<CdmKeyInformation> CdmKeysInfo;
-
-// An interface that represents the Content Decryption Module (CDM) in the
-// Encrypted Media Extensions (EME) spec in Chromium.
-// See http://w3c.github.io/encrypted-media/#cdm
-//
-// * Ownership
-//
-// This class is ref-counted. However, a ref-count should only be held by:
-// - The owner of the CDM. This is usually some class in the EME stack, e.g.
-//   CdmSessionAdapter in the render process, or MojoCdmService in a non-render
-//   process.
-// - The media player that uses the CDM, to prevent the CDM from being
-//   destructed while still being used by the media player.
-//
-// When binding class methods into callbacks, prefer WeakPtr to using |this|
-// directly to avoid having a ref-count held by the callback.
-//
-// * Thread Safety
-//
-// Most CDM operations happen on one thread. However, it is not uncommon that
-// the media player lives on a different thread and may call into the CDM from
-// that thread. For example, if the CDM supports a Decryptor interface, the
-// Decryptor methods could be called on a different thread. The CDM
-// implementation should make sure it's thread safe for these situations.
-//
-// TODO(xhwang): Rename MediaKeys to ContentDecryptionModule. See
-// http://crbug.com/309237
-
-class MEDIA_EXPORT MediaKeys
-    : public base::RefCountedThreadSafe<MediaKeys, MediaKeysTraits> {
- public:
-  // Type of license required when creating/loading a session.
-  // Must be consistent with the values specified in the spec:
-  // https://w3c.github.io/encrypted-media/#idl-def-MediaKeySessionType
-  enum SessionType {
-    TEMPORARY_SESSION,
-    PERSISTENT_LICENSE_SESSION,
-    PERSISTENT_RELEASE_MESSAGE_SESSION,
-    SESSION_TYPE_MAX = PERSISTENT_RELEASE_MESSAGE_SESSION
-  };
-
-  // Type of message being sent to the application.
-  // Must be consistent with the values specified in the spec:
-  // https://w3c.github.io/encrypted-media/#idl-def-MediaKeyMessageType
-  enum MessageType {
-    LICENSE_REQUEST,
-    LICENSE_RENEWAL,
-    LICENSE_RELEASE,
-    MESSAGE_TYPE_MAX = LICENSE_RELEASE
-  };
-
-  // Provides a server certificate to be used to encrypt messages to the
-  // license server.
-  virtual void SetServerCertificate(
-      const std::vector<uint8_t>& certificate,
-      std::unique_ptr<SimpleCdmPromise> promise) = 0;
-
-  // Creates a session with |session_type|. Then generates a request with the
-  // |init_data_type| and |init_data|.
-  // Note:
-  // 1. The session ID will be provided when the |promise| is resolved.
-  // 2. The generated request should be returned through a SessionMessageCB,
-  //    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. 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;
-
-  // Closes the session specified by |session_id|. The CDM should resolve or
-  // reject the |promise| when the call has been processed. This may be before
-  // the session is closed. Once the session is closed, a SessionClosedCB must
-  // also be called.
-  virtual void CloseSession(const std::string& session_id,
-                            std::unique_ptr<SimpleCdmPromise> promise) = 0;
-
-  // Removes stored session data associated with the session specified by
-  // |session_id|.
-  virtual void RemoveSession(const std::string& session_id,
-                             std::unique_ptr<SimpleCdmPromise> promise) = 0;
-
-  // Returns the CdmContext associated with |this|. The returned CdmContext is
-  // owned by |this| and the caller needs to make sure it is not used after
-  // |this| is destructed.
-  // Returns null if CdmContext is not supported. Instead the media player may
-  // use the CDM via some platform specific method.
-  // By default this method returns null.
-  // TODO(xhwang): Convert all SetCdm() implementations to use CdmContext so
-  // that this function should never return nullptr.
-  virtual CdmContext* GetCdmContext();
-
-  // Deletes |this| on the correct thread. By default |this| is deleted
-  // immediately. Override this method if |this| needs to be deleted on a
-  // specific thread.
-  virtual void DeleteOnCorrectThread() const;
-
- protected:
-  friend class base::RefCountedThreadSafe<MediaKeys, MediaKeysTraits>;
-
-  MediaKeys();
-  virtual ~MediaKeys();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(MediaKeys);
-};
-
-struct MEDIA_EXPORT MediaKeysTraits {
-  // Destroys |media_keys| on the correct thread.
-  static void Destruct(const MediaKeys* media_keys);
-};
-
-// CDM session event callbacks.
-
-// Called when the CDM needs to queue a message event to the session object.
-// See http://w3c.github.io/encrypted-media/#dom-evt-message
-typedef base::Callback<void(const std::string& session_id,
-                            MediaKeys::MessageType message_type,
-                            const std::vector<uint8_t>& message)>
-    SessionMessageCB;
-
-// Called when the session specified by |session_id| is closed. Note that the
-// CDM may close a session at any point, such as in response to a CloseSession()
-// call, when the session is no longer needed, or when system resources are
-// lost. See http://w3c.github.io/encrypted-media/#session-close
-typedef base::Callback<void(const std::string& session_id)> SessionClosedCB;
-
-// Called when there has been a change in the keys in the session or their
-// status. See http://w3c.github.io/encrypted-media/#dom-evt-keystatuseschange
-typedef base::Callback<void(const std::string& session_id,
-                            bool has_additional_usable_key,
-                            CdmKeysInfo keys_info)> SessionKeysChangeCB;
-
-// 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,
-                            base::Time new_expiry_time)>
-    SessionExpirationUpdateCB;
-
-}  // namespace media
-
-#endif  // MEDIA_BASE_MEDIA_KEYS_H_