Report change in session expiration

Bug: 19771612

Merged from Widevine CDM repo:
https://widevine-internal-review.googlesource.com/#/c/13885/

Change-Id: I754f06a7ed9476554f9e1da3fe23f4563f9fc07e

libwvdrmengine/mediadrm/src/WVDrmPlugin.cpp

@@ -954,6 +954,12 @@ void WVDrmPlugin::OnSessionExpiration(const CdmSessionId& cdmSessionId) {
   sendEvent(kDrmPluginEventKeyExpired, 0, &sessionId, NULL);
 }
 
+void WVDrmPlugin::OnExpirationUpdate(const CdmSessionId& cdmSessionId,
+                                     int64_t new_expiry_time) {
+  // TODO(kqyang): Glue with DrmPlugin API when it is ready. Note that
+  // new_expiry_time is in seconds while Android API is in milliseconds.
+}
+
 status_t WVDrmPlugin::mapAndNotifyOfCdmResponseType(
     const Vector<uint8_t>& sessionId,
     CdmResponseType res) {