Add PlayerTracker and BrowserCdm interfaces.

media/base/cdm_factory.h

-// 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.
-
-#ifndef MEDIA_BASE_CDM_FACTORY_H_
-#define MEDIA_BASE_CDM_FACTORY_H_
-
-#include <string>
-
-#include "base/memory/scoped_ptr.h"
-#include "media/base/media_export.h"
-#include "media/base/media_keys.h"
-
-namespace media {
-
-// Creates a CDM for |key_system|. Returns NULL if the CDM cannot be created.
-// TODO(xhwang): Add ifdef for IPC based CDM.
-scoped_ptr<MediaKeys> MEDIA_EXPORT
-    CreateBrowserCdm(const std::string& key_system,
-                     const SessionCreatedCB& session_created_cb,
-                     const SessionMessageCB& session_message_cb,
-                     const SessionReadyCB& session_ready_cb,
-                     const SessionClosedCB& session_closed_cb,
-                     const SessionErrorCB& session_error_cb);
-
-}  // namespace media
-
-#endif  // MEDIA_BASE_CDM_FACTORY_H_