Handle AirPlay key events properly

Fixes: videojs#159

src/plugin.js

@@ -227,6 +227,21 @@ const onPlayerReady = (player, emeError) => {
 
  setupSessions(player);
 
+ /*
+ * If playback is switched to AirPlay, we will receive another encrypted event,
+ * proxied from the AirPlay device, as is described here:
+ *
+ * https://developer.apple.com/streaming/fps/FairPlayStreamingOverview.pdf
+ *
+ * To accomodate for this, we should clear our list of sessions when the playback
+ * target changes, because the request is otherwise dropped as a duplicate.
+ */
+ if ('webkitCurrentPlaybackTargetIsWireless' in player.tech_.el_) {
+ player.tech_.el_.addEventListener('webkitcurrentplaybacktargetiswirelesschanged', () => {
+ player.eme.sessions = [];
+ });
+ }
+
  if (window.MediaKeys) {
  // Support EME 05 July 2016
  // Chrome 42+, Firefox 47+, Edge, Safari 12.1+ on macOS 10.14+