Make SingleSampleMediaSource provide a media item

This is part of go/exoplayer-playlist-retrieval which aims for all MediaSources to associate the media item to the corresponding window. Media items need to be added to the timeline which then assigns it to the window.mediaItem attribute.

PiperOrigin-RevId: 312065023

library/core/src/main/java/com/google/android/exoplayer2/source/DefaultMediaSourceFactory.java

@@ -22,7 +22,6 @@ import android.util.SparseArray;
 import androidx.annotation.Nullable;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlayerLibraryInfo;
 import com.google.android.exoplayer2.ExoPlayerLibraryInfo;
-import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.MediaItem;
 import com.google.android.exoplayer2.MediaItem;
 import com.google.android.exoplayer2.drm.DefaultDrmSessionManager;
 import com.google.android.exoplayer2.drm.DefaultDrmSessionManager;
 import com.google.android.exoplayer2.drm.DrmSessionManager;
 import com.google.android.exoplayer2.drm.DrmSessionManager;
@@ -299,16 +298,9 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
       SingleSampleMediaSource.Factory singleSampleSourceFactory =
       SingleSampleMediaSource.Factory singleSampleSourceFactory =
           new SingleSampleMediaSource.Factory(dataSourceFactory);
           new SingleSampleMediaSource.Factory(dataSourceFactory);
       for (int i = 0; i < subtitles.size(); i++) {
       for (int i = 0; i < subtitles.size(); i++) {
-        MediaItem.Subtitle subtitle = subtitles.get(i);
-        Format subtitleFormat =
-            new Format.Builder()
-                .setSampleMimeType(subtitle.mimeType)
-                .setLanguage(subtitle.language)
-                .setSelectionFlags(subtitle.selectionFlags)
-                .build();
         mediaSources[i + 1] =
         mediaSources[i + 1] =
             singleSampleSourceFactory.createMediaSource(
             singleSampleSourceFactory.createMediaSource(
-                subtitle.uri, subtitleFormat, /* durationUs= */ C.TIME_UNSET);
+                subtitles.get(i), /* durationUs= */ C.TIME_UNSET);
       }
       }
       mediaSource = new MergingMediaSource(mediaSources);
       mediaSource = new MergingMediaSource(mediaSources);
     }
     }