[Chromecast] Make EME persistent license support optional

chromecast/renderer/key_systems_cast.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 CHROMECAST_RENDERER_KEY_SYSTEMS_CAST_H_
 #define CHROMECAST_RENDERER_KEY_SYSTEMS_CAST_H_
 
 #include <memory>
 #include <vector>
 
 namespace media {
 class KeySystemProperties;
 }
 
 namespace chromecast {
 namespace shell {
 
 void AddChromecastKeySystems(
     std::vector<std::unique_ptr<::media::KeySystemProperties>>*
-        key_systems_properties);
+        key_systems_properties,
+    bool enable_persistent_license_support);
 
 }  // namespace shell
 }  // namespace chromecast
 
 #endif  // CHROMECAST_RENDERER_KEY_SYSTEMS_CAST_H_