perf: Close media source only on audio/video updates (#8826)

Author: tykus160

lib/media/streaming_engine.js

@@ -1285,6 +1285,7 @@ shaka.media.StreamingEngine = class {
   async onUpdate_(mediaState) {
     this.destroyer_.ensureNotDestroyed();
 
+    const ContentType = shaka.util.ManifestParserUtils.ContentType;
     const logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
 
     // Sanity check.
@@ -1361,7 +1362,17 @@ shaka.media.StreamingEngine = class {
       return;
     }
 
-    const mediaStates = Array.from(this.mediaStates_.values());
+    if (mediaState.type === ContentType.TEXT) {
+      // MSE endOfStream() closes MediaSource, not TextEngine, so skip here.
+      return;
+    }
+    const mediaStates = [mediaState];
+    const otherType = mediaState.type === ContentType.AUDIO ?
+        ContentType.VIDEO : ContentType.AUDIO;
+    const otherMediaState = this.mediaStates_.get(otherType);
+    if (otherMediaState) {
+      mediaStates.push(otherMediaState);
+    }
 
     // Check if we've buffered to the end of the presentation.  We delay adding
     // the audio and video media states, so it is possible for the text stream