EME: Allow temporary sessions to be removed for ClearKey only.

media/cdm/ppapi/external_clear_key/clear_key_cdm.h

Index: media/cdm/ppapi/external_clear_key/clear_key_cdm.h
diff --git a/media/cdm/ppapi/external_clear_key/clear_key_cdm.h b/media/cdm/ppapi/external_clear_key/clear_key_cdm.h
index a410aeeb2baa0468eda193502e82f779111583da..66b77e9f36f4e062d63e6cdef8cdb0bdc48a1c1a 100644
--- a/media/cdm/ppapi/external_clear_key/clear_key_cdm.h
+++ b/media/cdm/ppapi/external_clear_key/clear_key_cdm.h
@@ -100,6 +100,8 @@ class ClearKeyCdm : public ClearKeyCdmInterface {
                            bool has_additional_usable_key,
                            CdmKeysInfo keys_info);
   void OnSessionClosed(const std::string& session_id);
+  void OnSessionExpirationUpdate(const std::string& session_id,
+                                 base::Time new_expiry_time);
 
   // Handle the success/failure of a promise. These methods are responsible for
   // calling |host_| to resolve or reject the promise.