Forward TransferListener to media sources.

In the future, this allows to register the BandwidthMeter (managed by the player)
as a listener to all media transfers related to this media source.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=202643946

RELEASENOTES.md

@@ -18,8 +18,13 @@
 * Add support for lazy preparation of playlist media sources in
   `ConcatenatingMediaSource`
   ([#3972](https://github.com/google/ExoPlayer/issues/3972)).
-* Pass `BandwidthMeter` to `TrackSelection.Factory` which can be used to obtain
+* `BandwidthMeter` management (work in progress):
-  bandwidth estimates in the future. Always null at the moment.
+  * Pass `BandwidthMeter` to `TrackSelection.Factory` which can be used to
+    obtain bandwidth estimates in the future. Always null at the moment.
+  * Add method to `BandwidthMeter` to return the `TransferListener` used to
+    gather bandwidth information.
+  * Pass `TransferListener` to `MediaSource`s to listen to media data transfers.
+    Always null at the moment.
 * Error handling:
   * Allow configuration of the Loader retry delay
     ([#3370](https://github.com/google/ExoPlayer/issues/3370)).
@@ -29,8 +34,6 @@
 * DRM:
   * Allow DrmInitData to carry a license server URL
     ([#3393](https://github.com/google/ExoPlayer/issues/3393)).
-* Add method to `BandwidthMeter` to return the `TransferListener` used to gather
-  bandwidth information.
 * Add callback to `VideoListener` to notify of surface size changes.
 * Fix bug when reporting buffered position for multi-period windows and add
   two additional convenience methods `Player.getTotalBufferedDuration` and

extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsMediaSource.java

@@ -27,6 +27,7 @@ import com.google.android.exoplayer2.source.MediaSource.SourceInfoRefreshListene
 import com.google.android.exoplayer2.source.ads.AdsMediaSource;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.DataSource;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import java.io.IOException;
 
 /**
@@ -76,8 +77,12 @@ public final class ImaAdsMediaSource extends BaseMediaSource implements SourceIn
   }
 
   @Override
-  public void prepareSourceInternal(final ExoPlayer player, boolean isTopLevelSource) {
+  public void prepareSourceInternal(
-    adsMediaSource.prepareSource(player, isTopLevelSource, /* listener= */ this);
+      final ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
+    adsMediaSource.prepareSource(
+        player, isTopLevelSource, /* listener= */ this, mediaTransferListener);
   }
 
   @Override

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java

@@ -393,7 +393,11 @@ import java.util.Collections;
     loadControl.onPrepared();
     this.mediaSource = mediaSource;
     setState(Player.STATE_BUFFERING);
-    mediaSource.prepareSource(player, /* isTopLevelSource= */ true, /* listener= */ this);
+    mediaSource.prepareSource(
+        player,
+        /* isTopLevelSource= */ true,
+        /* listener= */ this,
+        /* mediaTransferListener= */ null);
     handler.sendEmptyMessage(MSG_DO_SOME_WORK);
   }
 

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

@@ -19,6 +19,7 @@ import android.os.Handler;
 import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.Timeline;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import java.util.ArrayList;
 
@@ -34,9 +35,9 @@ public abstract class BaseMediaSource implements MediaSource {
   private final ArrayList<SourceInfoRefreshListener> sourceInfoListeners;
   private final MediaSourceEventListener.EventDispatcher eventDispatcher;
 
-  private ExoPlayer player;
+  private @Nullable ExoPlayer player;
-  private Timeline timeline;
+  private @Nullable Timeline timeline;
-  private Object manifest;
+  private @Nullable Object manifest;
 
   public BaseMediaSource() {
     sourceInfoListeners = new ArrayList<>(/* initialCapacity= */ 1);
@@ -51,12 +52,19 @@ public abstract class BaseMediaSource implements MediaSource {
    * @param isTopLevelSource Whether this source has been passed directly to {@link
    *     ExoPlayer#prepare(MediaSource)} or {@link ExoPlayer#prepare(MediaSource, boolean,
    *     boolean)}.
+   * @param mediaTransferListener The transfer listener which should be informed of any media data
+   *     transfers. May be null if no listener is available. Note that this listener should usually
+   *     be only informed of transfers related to the media loads and not of auxiliary loads for
+   *     manifests and other data.
    */
-  protected abstract void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource);
+  protected abstract void prepareSourceInternal(
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener);
 
   /**
    * Releases the source. This method is called exactly once after each call to {@link
-   * #prepareSourceInternal(ExoPlayer, boolean)}.
+   * #prepareSourceInternal(ExoPlayer, boolean, TransferListener)}.
    */
   protected abstract void releaseSourceInternal();
 
@@ -129,12 +137,15 @@ public abstract class BaseMediaSource implements MediaSource {
 
   @Override
   public final void prepareSource(
-      ExoPlayer player, boolean isTopLevelSource, SourceInfoRefreshListener listener) {
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      SourceInfoRefreshListener listener,
+      @Nullable TransferListener<?> mediaTransferListener) {
     Assertions.checkArgument(this.player == null || this.player == player);
     sourceInfoListeners.add(listener);
     if (this.player == null) {
       this.player = player;
-      prepareSourceInternal(player, isTopLevelSource);
+      prepareSourceInternal(player, isTopLevelSource, mediaTransferListener);
     } else if (timeline != null) {
       listener.onSourceInfoRefreshed(/* source= */ this, timeline, manifest);
     }

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

@@ -21,6 +21,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.upstream.Allocator;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import java.io.IOException;
 import java.lang.annotation.Retention;
@@ -211,8 +212,11 @@ public final class ClippingMediaSource extends CompositeMediaSource<Void> {
   }
 
   @Override
-  public void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource) {
+  public void prepareSourceInternal(
-    super.prepareSourceInternal(player, isTopLevelSource);
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
+    super.prepareSourceInternal(player, isTopLevelSource, mediaTransferListener);
     prepareChildSource(/* id= */ null, mediaSource);
   }
 

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

@@ -21,6 +21,7 @@ import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.source.MediaSourceEventListener.MediaLoadData;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
@@ -37,6 +38,7 @@ public abstract class CompositeMediaSource<T> extends BaseMediaSource {
 
   private @Nullable ExoPlayer player;
   private @Nullable Handler eventHandler;
+  private @Nullable TransferListener<?> mediaTransferListener;
 
   /** Create composite media source without child sources. */
   protected CompositeMediaSource() {
@@ -45,8 +47,12 @@ public abstract class CompositeMediaSource<T> extends BaseMediaSource {
 
   @Override
   @CallSuper
-  public void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource) {
+  public void prepareSourceInternal(
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
     this.player = player;
+    this.mediaTransferListener = mediaTransferListener;
     eventHandler = new Handler();
   }
 
@@ -107,7 +113,10 @@ public abstract class CompositeMediaSource<T> extends BaseMediaSource {
     childSources.put(id, new MediaSourceAndListener(mediaSource, sourceListener, eventListener));
     mediaSource.addEventListener(Assertions.checkNotNull(eventHandler), eventListener);
     mediaSource.prepareSource(
-        Assertions.checkNotNull(player), /* isTopLevelSource= */ false, sourceListener);
+        Assertions.checkNotNull(player),
+        /* isTopLevelSource= */ false,
+        sourceListener,
+        mediaTransferListener);
   }
 
   /**

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

@@ -26,6 +26,7 @@ import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.source.ConcatenatingMediaSource.MediaSourceHolder;
 import com.google.android.exoplayer2.source.ShuffleOrder.DefaultShuffleOrder;
 import com.google.android.exoplayer2.upstream.Allocator;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.util.ArrayList;
@@ -373,8 +374,11 @@ public class ConcatenatingMediaSource extends CompositeMediaSource<MediaSourceHo
   }
 
   @Override
-  public final synchronized void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource) {
+  public final synchronized void prepareSourceInternal(
-    super.prepareSourceInternal(player, isTopLevelSource);
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
+    super.prepareSourceInternal(player, isTopLevelSource, mediaTransferListener);
     this.player = player;
     playerApplicationHandler = new Handler(player.getApplicationLooper());
     if (mediaSourcesPublic.isEmpty()) {

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

@@ -27,6 +27,7 @@ import com.google.android.exoplayer2.extractor.ExtractorsFactory;
 import com.google.android.exoplayer2.source.ads.AdsMediaSource;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.DataSource;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import java.io.IOException;
 
@@ -344,7 +345,10 @@ public final class ExtractorMediaSource extends BaseMediaSource
   }
 
   @Override
-  public void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource) {
+  public void prepareSourceInternal(
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
     notifySourceInfoRefreshed(timelineDurationUs, /* isSeekable= */ false);
   }
 

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

@@ -22,6 +22,7 @@ import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.source.ShuffleOrder.UnshuffledShuffleOrder;
 import com.google.android.exoplayer2.upstream.Allocator;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 
 /**
@@ -60,8 +61,11 @@ public final class LoopingMediaSource extends CompositeMediaSource<Void> {
   }
 
   @Override
-  public void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource) {
+  public void prepareSourceInternal(
-    super.prepareSourceInternal(player, isTopLevelSource);
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
+    super.prepareSourceInternal(player, isTopLevelSource, mediaTransferListener);
     prepareChildSource(/* id= */ null, childSource);
   }
 

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

@@ -21,6 +21,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.upstream.Allocator;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import java.io.IOException;
 
 /**
@@ -32,7 +33,7 @@ import java.io.IOException;
  *       provide a new timeline whenever the structure of the media changes. The MediaSource
  *       provides these timelines by calling {@link SourceInfoRefreshListener#onSourceInfoRefreshed}
  *       on the {@link SourceInfoRefreshListener}s passed to {@link #prepareSource(ExoPlayer,
- *       boolean, SourceInfoRefreshListener)}.
+ *       boolean, SourceInfoRefreshListener, TransferListener)}.
  *   <li>To provide {@link MediaPeriod} instances for the periods in its timeline. MediaPeriods are
  *       obtained by calling {@link #createPeriod(MediaPeriodId, Allocator)}, and provide a way for
  *       the player to load and read the media.
@@ -206,9 +207,16 @@ public interface MediaSource {
    *     boolean)}. If {@code false}, this source is being prepared by another source (e.g. {@link
    *     ConcatenatingMediaSource}) for composition.
    * @param listener The listener to be added.
+   * @param mediaTransferListener The transfer listener which should be informed of any media data
+   *     transfers. May be null if no listener is available. Note that this listener should be only
+   *     informed of transfers related to the media loads and not of auxiliary loads for manifests
+   *     and other data.
    */
   void prepareSource(
-      ExoPlayer player, boolean isTopLevelSource, SourceInfoRefreshListener listener);
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      SourceInfoRefreshListener listener,
+      @Nullable TransferListener<?> mediaTransferListener);
 
   /**
    * Throws any pending error encountered while loading or refreshing source information.

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

@@ -20,6 +20,7 @@ import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.upstream.Allocator;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import java.io.IOException;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -97,8 +98,11 @@ public final class MergingMediaSource extends CompositeMediaSource<Integer> {
   }
 
   @Override
-  public void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource) {
+  public void prepareSourceInternal(
-    super.prepareSourceInternal(player, isTopLevelSource);
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
+    super.prepareSourceInternal(player, isTopLevelSource, mediaTransferListener);
     for (int i = 0; i < mediaSources.length; i++) {
       prepareChildSource(i, mediaSources[i]);
     }

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

@@ -24,6 +24,7 @@ import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import java.io.IOException;
 
@@ -268,7 +269,10 @@ public final class SingleSampleMediaSource extends BaseMediaSource {
   // MediaSource implementation.
 
   @Override
-  public void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource) {
+  public void prepareSourceInternal(
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
     refreshSourceInfo(timeline, /* manifest= */ null);
   }
 

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

@@ -36,6 +36,7 @@ import com.google.android.exoplayer2.source.MediaSourceEventListener.MediaLoadDa
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import java.io.IOException;
 import java.lang.annotation.Retention;
@@ -305,8 +306,11 @@ public final class AdsMediaSource extends CompositeMediaSource<MediaPeriodId> {
   }
 
   @Override
-  public void prepareSourceInternal(final ExoPlayer player, boolean isTopLevelSource) {
+  public void prepareSourceInternal(
-    super.prepareSourceInternal(player, isTopLevelSource);
+      final ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
+    super.prepareSourceInternal(player, isTopLevelSource, mediaTransferListener);
     Assertions.checkArgument(isTopLevelSource);
     final ComponentListener componentListener = new ComponentListener();
     this.componentListener = componentListener;

library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java

@@ -18,6 +18,7 @@ package com.google.android.exoplayer2;
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.fail;
 
+import android.support.annotation.Nullable;
 import android.view.Surface;
 import com.google.android.exoplayer2.Player.EventListener;
 import com.google.android.exoplayer2.Timeline.Window;
@@ -44,6 +45,7 @@ import com.google.android.exoplayer2.testutil.FakeTrackSelection;
 import com.google.android.exoplayer2.testutil.FakeTrackSelector;
 import com.google.android.exoplayer2.testutil.RobolectricUtil;
 import com.google.android.exoplayer2.upstream.Allocator;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -229,8 +231,10 @@ public final class ExoPlayerTest {
         new FakeMediaSource(timeline, new Object(), Builder.VIDEO_FORMAT) {
           @Override
           public synchronized void prepareSourceInternal(
-              ExoPlayer player, boolean isTopLevelSource) {
+              ExoPlayer player,
-            super.prepareSourceInternal(player, isTopLevelSource);
+              boolean isTopLevelSource,
+              @Nullable TransferListener<?> mediaTransferListener) {
+            super.prepareSourceInternal(player, isTopLevelSource, mediaTransferListener);
             // We've queued a source info refresh on the playback thread's event queue. Allow the
             // test thread to prepare the player with the third source, and block this thread (the
             // playback thread) until the test thread's call to prepare() has returned.

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java

@@ -46,6 +46,7 @@ import com.google.android.exoplayer2.upstream.Loader;
 import com.google.android.exoplayer2.upstream.Loader.LoadErrorAction;
 import com.google.android.exoplayer2.upstream.LoaderErrorThrower;
 import com.google.android.exoplayer2.upstream.ParsingLoadable;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.io.BufferedReader;
@@ -544,7 +545,10 @@ public final class DashMediaSource extends BaseMediaSource {
   // MediaSource implementation.
 
   @Override
-  public void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource) {
+  public void prepareSourceInternal(
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
     if (sideloadedManifest) {
       processManifest(false);
     } else {

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaSource.java

@@ -40,6 +40,7 @@ import com.google.android.exoplayer2.source.hls.playlist.HlsPlaylistTracker;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.ParsingLoadable;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import java.io.IOException;
 import java.util.List;
@@ -367,7 +368,10 @@ public final class HlsMediaSource extends BaseMediaSource
   }
 
   @Override
-  public void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource) {
+  public void prepareSourceInternal(
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
     EventDispatcher eventDispatcher = createEventDispatcher(/* mediaPeriodId= */ null);
     playlistTracker.start(manifestUri, eventDispatcher, /* listener= */ this);
   }

library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/SsMediaSource.java

@@ -44,6 +44,7 @@ import com.google.android.exoplayer2.upstream.Loader;
 import com.google.android.exoplayer2.upstream.Loader.LoadErrorAction;
 import com.google.android.exoplayer2.upstream.LoaderErrorThrower;
 import com.google.android.exoplayer2.upstream.ParsingLoadable;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -462,7 +463,10 @@ public final class SsMediaSource extends BaseMediaSource
   // MediaSource implementation.
 
   @Override
-  public void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource) {
+  public void prepareSourceInternal(
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
     if (sideloadedManifest) {
       manifestLoaderErrorThrower = new LoaderErrorThrower.Dummy();
       processManifest();

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaSource.java

@@ -36,6 +36,7 @@ import com.google.android.exoplayer2.source.TrackGroup;
 import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.DataSpec;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -86,7 +87,10 @@ public class FakeMediaSource extends BaseMediaSource {
   }
 
   @Override
-  public synchronized void prepareSourceInternal(ExoPlayer player, boolean isTopLevelSource) {
+  public synchronized void prepareSourceInternal(
+      ExoPlayer player,
+      boolean isTopLevelSource,
+      @Nullable TransferListener<?> mediaTransferListener) {
     assertThat(preparedSource).isFalse();
     preparedSource = true;
     releasedSource = false;

testutils_robolectric/src/main/java/com/google/android/exoplayer2/testutil/MediaSourceTestRunner.java

@@ -126,7 +126,11 @@ public class MediaSourceTestRunner {
         new Runnable() {
           @Override
           public void run() {
-            mediaSource.prepareSource(player, true, mediaSourceListener);
+            mediaSource.prepareSource(
+                player,
+                /* isTopLevelSource= */ true,
+                mediaSourceListener,
+                /* mediaTransferListener= */ null);
             try {
               // TODO: This only catches errors that are set synchronously in prepareSource. To
               // capture async errors we'll need to poll maybeThrowSourceInfoRefreshError until the