Add PlayerTracker and BrowserCdm interfaces.

media/base/browser_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_
+#ifndef MEDIA_BASE_BROWSER_CDM_FACTORY_H_
+#define MEDIA_BASE_BROWSER_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.
+class BrowserCdm;
+
+// Creates a BrowserCdm for |key_system|. Returns NULL if the CDM cannot be
+// created.
 // TODO(xhwang): Add ifdef for IPC based CDM.
-scoped_ptr<MediaKeys> MEDIA_EXPORT
+scoped_ptr<BrowserCdm> 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_
+#endif  // MEDIA_BASE_BROWSER_CDM_FACTORY_H_