Make ExtractorMediaSource a CompositeMediaSource instead of just wrapping.

It's easy to forget to forward methods when using basic wrapping. For example,
ExtractorMediaSource.addEventListener is currently a no-op because it's not
forwarded.

PiperOrigin-RevId: 257757556

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

@@ -35,8 +35,7 @@ import java.io.IOException;
 /** @deprecated Use {@link ProgressiveMediaSource} instead. */
 @Deprecated
 @SuppressWarnings("deprecation")
-public final class ExtractorMediaSource extends BaseMediaSource
-    implements MediaSource.SourceInfoRefreshListener {
+public final class ExtractorMediaSource extends CompositeMediaSource<Void> {
 
   /** @deprecated Use {@link MediaSourceEventListener} instead. */
   @Deprecated
@@ -340,12 +339,14 @@ public final class ExtractorMediaSource extends BaseMediaSource
 
   @Override
   protected void prepareSourceInternal(@Nullable TransferListener mediaTransferListener) {
-    progressiveMediaSource.prepareSource(/* listener= */ this, mediaTransferListener);
+    super.prepareSourceInternal(mediaTransferListener);
+    prepareChildSource(/* id= */ null, progressiveMediaSource);
   }
 
   @Override
-  public void maybeThrowSourceInfoRefreshError() throws IOException {
-    progressiveMediaSource.maybeThrowSourceInfoRefreshError();
+  protected void onChildSourceInfoRefreshed(
+      @Nullable Void id, MediaSource mediaSource, Timeline timeline) {
+    refreshSourceInfo(timeline);
   }
 
   @Override
@@ -358,16 +359,6 @@ public final class ExtractorMediaSource extends BaseMediaSource
     progressiveMediaSource.releasePeriod(mediaPeriod);
   }
 
-  @Override
-  protected void releaseSourceInternal() {
-    progressiveMediaSource.releaseSource(/* listener= */ this);
-  }
-
-  @Override
-  public void onSourceInfoRefreshed(MediaSource source, Timeline timeline) {
-    refreshSourceInfo(timeline);
-  }
-
   @Deprecated
   private static final class EventListenerWrapper extends DefaultMediaSourceEventListener {