Forward TransferListener from MediaSources to DataSources.

This wires up recent changes of passing a transfer listener to the MediaSource and
allowing DataSources to accept new listeners.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=203280818

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

@@ -68,40 +68,6 @@ public final class ExtractorMediaSource extends BaseMediaSource
 
   }
 
-  /**
-   * The default minimum number of times to retry loading prior to failing for on-demand streams.
-   */
-  public static final int DEFAULT_MIN_LOADABLE_RETRY_COUNT_ON_DEMAND = 3;
-
-  /**
-   * The default minimum number of times to retry loading prior to failing for live streams.
-   */
-  public static final int DEFAULT_MIN_LOADABLE_RETRY_COUNT_LIVE = 6;
-
-  /**
-   * Value for {@code minLoadableRetryCount} that causes the loader to retry
-   * {@link #DEFAULT_MIN_LOADABLE_RETRY_COUNT_LIVE} times for live streams and
-   * {@link #DEFAULT_MIN_LOADABLE_RETRY_COUNT_ON_DEMAND} for on-demand streams.
-   */
-  public static final int MIN_RETRY_COUNT_DEFAULT_FOR_MEDIA = -1;
-
-  /**
-   * The default number of bytes that should be loaded between each each invocation of
-   * {@link MediaPeriod.Callback#onContinueLoadingRequested(SequenceableLoader)}.
-   */
-  public static final int DEFAULT_LOADING_CHECK_INTERVAL_BYTES = 1024 * 1024;
-
-  private final Uri uri;
-  private final DataSource.Factory dataSourceFactory;
-  private final ExtractorsFactory extractorsFactory;
-  private final int minLoadableRetryCount;
-  private final String customCacheKey;
-  private final int continueLoadingCheckIntervalBytes;
-  private final @Nullable Object tag;
-
-  private long timelineDurationUs;
-  private boolean timelineIsSeekable;
-
   /** Factory for {@link ExtractorMediaSource}s. */
   public static final class Factory implements AdsMediaSource.MediaSourceFactory {
 
@@ -244,6 +210,39 @@ public final class ExtractorMediaSource extends BaseMediaSource
     }
   }
 
+  /**
+   * The default minimum number of times to retry loading prior to failing for on-demand streams.
+   */
+  public static final int DEFAULT_MIN_LOADABLE_RETRY_COUNT_ON_DEMAND = 3;
+
+  /** The default minimum number of times to retry loading prior to failing for live streams. */
+  public static final int DEFAULT_MIN_LOADABLE_RETRY_COUNT_LIVE = 6;
+
+  /**
+   * Value for {@code minLoadableRetryCount} that causes the loader to retry {@link
+   * #DEFAULT_MIN_LOADABLE_RETRY_COUNT_LIVE} times for live streams and {@link
+   * #DEFAULT_MIN_LOADABLE_RETRY_COUNT_ON_DEMAND} for on-demand streams.
+   */
+  public static final int MIN_RETRY_COUNT_DEFAULT_FOR_MEDIA = -1;
+
+  /**
+   * The default number of bytes that should be loaded between each each invocation of {@link
+   * MediaPeriod.Callback#onContinueLoadingRequested(SequenceableLoader)}.
+   */
+  public static final int DEFAULT_LOADING_CHECK_INTERVAL_BYTES = 1024 * 1024;
+
+  private final Uri uri;
+  private final DataSource.Factory dataSourceFactory;
+  private final ExtractorsFactory extractorsFactory;
+  private final int minLoadableRetryCount;
+  private final String customCacheKey;
+  private final int continueLoadingCheckIntervalBytes;
+  private final @Nullable Object tag;
+
+  private long timelineDurationUs;
+  private boolean timelineIsSeekable;
+  private @Nullable TransferListener<? super DataSource> transferListener;
+
   /**
    * @param uri The {@link Uri} of the media stream.
    * @param dataSourceFactory A factory for {@link DataSource}s to read the media.
@@ -349,6 +348,7 @@ public final class ExtractorMediaSource extends BaseMediaSource
       ExoPlayer player,
       boolean isTopLevelSource,
       @Nullable TransferListener<? super DataSource> mediaTransferListener) {
+    transferListener = mediaTransferListener;
     notifySourceInfoRefreshed(timelineDurationUs, /* isSeekable= */ false);
   }
 
@@ -360,9 +360,13 @@ public final class ExtractorMediaSource extends BaseMediaSource
   @Override
   public MediaPeriod createPeriod(MediaPeriodId id, Allocator allocator) {
     Assertions.checkArgument(id.periodIndex == 0);
+    DataSource dataSource = dataSourceFactory.createDataSource();
+    if (transferListener != null) {
+      dataSource.addTransferListener(transferListener);
+    }
     return new ExtractorMediaPeriod(
         uri,
-        dataSourceFactory.createDataSource(),
+        dataSource,
         extractorsFactory.createExtractors(),
         minLoadableRetryCount,
         createEventDispatcher(id),

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

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer2.source;
 
+import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.FormatHolder;
@@ -28,6 +29,7 @@ import com.google.android.exoplayer2.upstream.Loader;
 import com.google.android.exoplayer2.upstream.Loader.LoadErrorAction;
 import com.google.android.exoplayer2.upstream.Loader.Loadable;
 import com.google.android.exoplayer2.upstream.StatsDataSource;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
@@ -47,6 +49,7 @@ import java.util.Arrays;
 
   private final DataSpec dataSpec;
   private final DataSource.Factory dataSourceFactory;
+  private final @Nullable TransferListener<? super DataSource> transferListener;
   private final int minLoadableRetryCount;
   private final EventDispatcher eventDispatcher;
   private final TrackGroupArray tracks;
@@ -67,6 +70,7 @@ import java.util.Arrays;
   public SingleSampleMediaPeriod(
       DataSpec dataSpec,
       DataSource.Factory dataSourceFactory,
+      @Nullable TransferListener<? super DataSource> transferListener,
       Format format,
       long durationUs,
       int minLoadableRetryCount,
@@ -74,6 +78,7 @@ import java.util.Arrays;
       boolean treatLoadErrorsAsEndOfStream) {
     this.dataSpec = dataSpec;
     this.dataSourceFactory = dataSourceFactory;
+    this.transferListener = transferListener;
     this.format = format;
     this.durationUs = durationUs;
     this.minLoadableRetryCount = minLoadableRetryCount;
@@ -138,11 +143,13 @@ import java.util.Arrays;
     if (loadingFinished || loader.isLoading()) {
       return false;
     }
+    DataSource dataSource = dataSourceFactory.createDataSource();
+    if (transferListener != null) {
+      dataSource.addTransferListener(transferListener);
+    }
     long elapsedRealtimeMs =
         loader.startLoading(
-            new SourceLoadable(dataSpec, dataSourceFactory.createDataSource()),
+            new SourceLoadable(dataSpec, dataSource), /* callback= */ this, minLoadableRetryCount);
-            this,
-            minLoadableRetryCount);
     eventDispatcher.loadStarted(
         dataSpec,
         dataSpec.uri,

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

@@ -169,6 +169,8 @@ public final class SingleSampleMediaSource extends BaseMediaSource {
   private final boolean treatLoadErrorsAsEndOfStream;
   private final Timeline timeline;
 
+  private @Nullable TransferListener<? super DataSource> transferListener;
+
   /**
    * @param uri The {@link Uri} of the media stream.
    * @param dataSourceFactory The factory from which the {@link DataSource} to read the media will
@@ -273,6 +275,7 @@ public final class SingleSampleMediaSource extends BaseMediaSource {
       ExoPlayer player,
       boolean isTopLevelSource,
       @Nullable TransferListener<? super DataSource> mediaTransferListener) {
+    transferListener = mediaTransferListener;
     refreshSourceInfo(timeline, /* manifest= */ null);
   }
 
@@ -287,6 +290,7 @@ public final class SingleSampleMediaSource extends BaseMediaSource {
     return new SingleSampleMediaPeriod(
         dataSpec,
         dataSourceFactory,
+        transferListener,
         format,
         durationUs,
         minLoadableRetryCount,

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

@@ -581,7 +581,8 @@ public final class ExoPlayerTest {
               MediaPeriodId id,
               TrackGroupArray trackGroupArray,
               Allocator allocator,
-              EventDispatcher eventDispatcher) {
+              EventDispatcher eventDispatcher,
+              @Nullable TransferListener<? super DataSource> transferListener) {
             FakeMediaPeriod mediaPeriod = new FakeMediaPeriod(trackGroupArray, eventDispatcher);
             mediaPeriod.setSeekToUsOffset(10);
             return mediaPeriod;
@@ -615,7 +616,8 @@ public final class ExoPlayerTest {
               MediaPeriodId id,
               TrackGroupArray trackGroupArray,
               Allocator allocator,
-              EventDispatcher eventDispatcher) {
+              EventDispatcher eventDispatcher,
+              @Nullable TransferListener<? super DataSource> transferListener) {
             FakeMediaPeriod mediaPeriod = new FakeMediaPeriod(trackGroupArray, eventDispatcher);
             mediaPeriod.setDiscontinuityPositionUs(10);
             return mediaPeriod;
@@ -640,7 +642,8 @@ public final class ExoPlayerTest {
               MediaPeriodId id,
               TrackGroupArray trackGroupArray,
               Allocator allocator,
-              EventDispatcher eventDispatcher) {
+              EventDispatcher eventDispatcher,
+              @Nullable TransferListener<? super DataSource> transferListener) {
             FakeMediaPeriod mediaPeriod = new FakeMediaPeriod(trackGroupArray, eventDispatcher);
             mediaPeriod.setDiscontinuityPositionUs(0);
             return mediaPeriod;
@@ -876,7 +879,8 @@ public final class ExoPlayerTest {
               MediaPeriodId id,
               TrackGroupArray trackGroupArray,
               Allocator allocator,
-              EventDispatcher eventDispatcher) {
+              EventDispatcher eventDispatcher,
+              @Nullable TransferListener<? super DataSource> transferListener) {
             // Defer completing preparation of the period until playback parameters have been set.
             fakeMediaPeriodHolder[0] =
                 new FakeMediaPeriod(trackGroupArray, eventDispatcher, /* deferOnPrepared= */ true);

library/core/src/test/java/com/google/android/exoplayer2/source/ClippingMediaSourceTest.java

@@ -37,6 +37,8 @@ import com.google.android.exoplayer2.testutil.MediaSourceTestRunner;
 import com.google.android.exoplayer2.testutil.RobolectricUtil;
 import com.google.android.exoplayer2.testutil.TimelineAsserts;
 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;
 import org.junit.Before;
 import org.junit.Test;
@@ -478,7 +480,8 @@ public final class ClippingMediaSourceTest {
               MediaPeriodId id,
               TrackGroupArray trackGroupArray,
               Allocator allocator,
-              EventDispatcher eventDispatcher) {
+              EventDispatcher eventDispatcher,
+              @Nullable TransferListener<? super DataSource> transferListener) {
             eventDispatcher.downstreamFormatChanged(
                 new MediaLoadData(
                     C.DATA_TYPE_MEDIA,
@@ -488,7 +491,8 @@ public final class ClippingMediaSourceTest {
                     /* trackSelectionData= */ null,
                     C.usToMs(eventStartUs),
                     C.usToMs(eventEndUs)));
-            return super.createFakeMediaPeriod(id, trackGroupArray, allocator, eventDispatcher);
+            return super.createFakeMediaPeriod(
+                id, trackGroupArray, allocator, eventDispatcher, transferListener);
           }
         };
     final ClippingMediaSource clippingMediaSource =

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

@@ -21,7 +21,9 @@ import com.google.android.exoplayer2.source.chunk.ChunkSource;
 import com.google.android.exoplayer2.source.dash.PlayerEmsgHandler.PlayerTrackEmsgHandler;
 import com.google.android.exoplayer2.source.dash.manifest.DashManifest;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
+import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.LoaderErrorThrower;
+import com.google.android.exoplayer2.upstream.TransferListener;
 
 /**
  * An {@link ChunkSource} for DASH streams.
@@ -44,6 +46,8 @@ public interface DashChunkSource extends ChunkSource {
      *     message track.
      * @param enableCea608Track Whether the chunks generated by the source may output a CEA-608
      *     track.
+     * @param transferListener The transfer listener which should be informed of any data transfers.
+     *     May be null if no listener is available.
      * @return The created {@link DashChunkSource}.
      */
     DashChunkSource createDashChunkSource(
@@ -56,7 +60,8 @@ public interface DashChunkSource extends ChunkSource {
         long elapsedRealtimeOffsetMs,
         boolean enableEventMessageTrack,
         boolean enableCea608Track,
-        @Nullable PlayerTrackEmsgHandler playerEmsgHandler);
+        @Nullable PlayerTrackEmsgHandler playerEmsgHandler,
+        @Nullable TransferListener<? super DataSource> transferListener);
   }
 
   /**

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

@@ -43,7 +43,9 @@ import com.google.android.exoplayer2.source.dash.manifest.Period;
 import com.google.android.exoplayer2.source.dash.manifest.Representation;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.upstream.Allocator;
+import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.LoaderErrorThrower;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.MimeTypes;
 import java.io.IOException;
 import java.lang.annotation.Retention;
@@ -61,6 +63,7 @@ import java.util.List;
 
   /* package */ final int id;
   private final DashChunkSource.Factory chunkSourceFactory;
+  private final @Nullable TransferListener<? super DataSource> transferListener;
   private final int minLoadableRetryCount;
   private final EventDispatcher eventDispatcher;
   private final long elapsedRealtimeOffset;
@@ -87,6 +90,7 @@ import java.util.List;
       DashManifest manifest,
       int periodIndex,
       DashChunkSource.Factory chunkSourceFactory,
+      @Nullable TransferListener<? super DataSource> transferListener,
       int minLoadableRetryCount,
       EventDispatcher eventDispatcher,
       long elapsedRealtimeOffset,
@@ -98,6 +102,7 @@ import java.util.List;
     this.manifest = manifest;
     this.periodIndex = periodIndex;
     this.chunkSourceFactory = chunkSourceFactory;
+    this.transferListener = transferListener;
     this.minLoadableRetryCount = minLoadableRetryCount;
     this.eventDispatcher = eventDispatcher;
     this.elapsedRealtimeOffset = elapsedRealtimeOffset;
@@ -562,7 +567,8 @@ import java.util.List;
             elapsedRealtimeOffset,
             enableEventMessageTrack,
             enableCea608Track,
-            trackPlayerEmsgHandler);
+            trackPlayerEmsgHandler,
+            transferListener);
     ChunkSampleStream<DashChunkSource> stream =
         new ChunkSampleStream<>(
             trackGroupInfo.trackType,

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

@@ -315,6 +315,7 @@ public final class DashMediaSource extends BaseMediaSource {
 
   private DataSource dataSource;
   private Loader loader;
+  private @Nullable TransferListener<? super DataSource> mediaTransferListener;
 
   private IOException manifestFatalError;
   private Handler handler;
@@ -550,6 +551,7 @@ public final class DashMediaSource extends BaseMediaSource {
       ExoPlayer player,
       boolean isTopLevelSource,
       @Nullable TransferListener<? super DataSource> mediaTransferListener) {
+    this.mediaTransferListener = mediaTransferListener;
     if (sideloadedManifest) {
       processManifest(false);
     } else {
@@ -576,6 +578,7 @@ public final class DashMediaSource extends BaseMediaSource {
             manifest,
             periodIndex,
             chunkSourceFactory,
+            mediaTransferListener,
             minLoadableRetryCount,
             periodEventDispatcher,
             elapsedRealtimeOffsetMs,

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

@@ -50,6 +50,7 @@ import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
 import com.google.android.exoplayer2.upstream.HttpDataSource.InvalidResponseCodeException;
 import com.google.android.exoplayer2.upstream.LoaderErrorThrower;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
@@ -87,8 +88,12 @@ public class DefaultDashChunkSource implements DashChunkSource {
         long elapsedRealtimeOffsetMs,
         boolean enableEventMessageTrack,
         boolean enableCea608Track,
-        @Nullable PlayerTrackEmsgHandler playerEmsgHandler) {
+        @Nullable PlayerTrackEmsgHandler playerEmsgHandler,
+        @Nullable TransferListener<? super DataSource> transferListener) {
       DataSource dataSource = dataSourceFactory.createDataSource();
+      if (transferListener != null) {
+        dataSource.addTransferListener(transferListener);
+      }
       return new DefaultDashChunkSource(
           manifestLoaderErrorThrower,
           manifest,

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

@@ -17,6 +17,7 @@ package com.google.android.exoplayer2.source.hls;
 
 import android.net.Uri;
 import android.os.SystemClock;
+import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.source.BehindLiveWindowException;
@@ -32,6 +33,7 @@ import com.google.android.exoplayer2.trackselection.BaseTrackSelection;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 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.TimestampAdjuster;
 import com.google.android.exoplayer2.util.UriUtil;
 import com.google.android.exoplayer2.util.Util;
@@ -114,15 +116,22 @@ import java.util.List;
    * @param variants The available variants.
    * @param dataSourceFactory An {@link HlsDataSourceFactory} to create {@link DataSource}s for the
    *     chunks.
-   * @param timestampAdjusterProvider A provider of {@link TimestampAdjuster} instances. If
+   * @param mediaTransferListener The transfer listener which should be informed of any media data
-   *     multiple {@link HlsChunkSource}s are used for a single playback, they should all share the
+   *     transfers. May be null if no listener is available.
-   *     same provider.
+   * @param timestampAdjusterProvider A provider of {@link TimestampAdjuster} instances. If multiple
+   *     {@link HlsChunkSource}s are used for a single playback, they should all share the same
+   *     provider.
    * @param muxedCaptionFormats List of muxed caption {@link Format}s. Null if no closed caption
    *     information is available in the master playlist.
    */
-  public HlsChunkSource(HlsExtractorFactory extractorFactory, HlsPlaylistTracker playlistTracker,
+  public HlsChunkSource(
-      HlsUrl[] variants, HlsDataSourceFactory dataSourceFactory,
+      HlsExtractorFactory extractorFactory,
-      TimestampAdjusterProvider timestampAdjusterProvider, List<Format> muxedCaptionFormats) {
+      HlsPlaylistTracker playlistTracker,
+      HlsUrl[] variants,
+      HlsDataSourceFactory dataSourceFactory,
+      @Nullable TransferListener<? super DataSource> mediaTransferListener,
+      TimestampAdjusterProvider timestampAdjusterProvider,
+      List<Format> muxedCaptionFormats) {
     this.extractorFactory = extractorFactory;
     this.playlistTracker = playlistTracker;
     this.variants = variants;
@@ -136,6 +145,9 @@ import java.util.List;
       initialTrackSelection[i] = i;
     }
     mediaDataSource = dataSourceFactory.createDataSource(C.DATA_TYPE_MEDIA);
+    if (mediaTransferListener != null) {
+      mediaDataSource.addTransferListener(mediaTransferListener);
+    }
     encryptionDataSource = dataSourceFactory.createDataSource(C.DATA_TYPE_DRM);
     trackGroup = new TrackGroup(variantFormats);
     trackSelection = new InitializationTrackSelection(trackGroup, initialTrackSelection);

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

@@ -31,6 +31,8 @@ import com.google.android.exoplayer2.source.hls.playlist.HlsMasterPlaylist.HlsUr
 import com.google.android.exoplayer2.source.hls.playlist.HlsPlaylistTracker;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 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 com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
@@ -50,6 +52,7 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
   private final HlsExtractorFactory extractorFactory;
   private final HlsPlaylistTracker playlistTracker;
   private final HlsDataSourceFactory dataSourceFactory;
+  private final @Nullable TransferListener<? super DataSource> mediaTransferListener;
   private final int minLoadableRetryCount;
   private final EventDispatcher eventDispatcher;
   private final Allocator allocator;
@@ -70,6 +73,7 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
       HlsExtractorFactory extractorFactory,
       HlsPlaylistTracker playlistTracker,
       HlsDataSourceFactory dataSourceFactory,
+      @Nullable TransferListener<? super DataSource> mediaTransferListener,
       int minLoadableRetryCount,
       EventDispatcher eventDispatcher,
       Allocator allocator,
@@ -78,6 +82,7 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
     this.extractorFactory = extractorFactory;
     this.playlistTracker = playlistTracker;
     this.dataSourceFactory = dataSourceFactory;
+    this.mediaTransferListener = mediaTransferListener;
     this.minLoadableRetryCount = minLoadableRetryCount;
     this.eventDispatcher = eventDispatcher;
     this.allocator = allocator;
@@ -488,8 +493,15 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
 
   private HlsSampleStreamWrapper buildSampleStreamWrapper(int trackType, HlsUrl[] variants,
       Format muxedAudioFormat, List<Format> muxedCaptionFormats, long positionUs) {
-    HlsChunkSource defaultChunkSource = new HlsChunkSource(extractorFactory, playlistTracker,
+    HlsChunkSource defaultChunkSource =
-        variants, dataSourceFactory, timestampAdjusterProvider, muxedCaptionFormats);
+        new HlsChunkSource(
+            extractorFactory,
+            playlistTracker,
+            variants,
+            dataSourceFactory,
+            mediaTransferListener,
+            timestampAdjusterProvider,
+            muxedCaptionFormats);
     return new HlsSampleStreamWrapper(trackType, this, defaultChunkSource, allocator, positionUs,
         muxedAudioFormat, minLoadableRetryCount, eventDispatcher);
   }

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

@@ -265,6 +265,8 @@ public final class HlsMediaSource extends BaseMediaSource
   private final HlsPlaylistTracker playlistTracker;
   private final @Nullable Object tag;
 
+  private @Nullable TransferListener<? super DataSource> mediaTransferListener;
+
   /**
    * @param manifestUri The {@link Uri} of the HLS manifest.
    * @param dataSourceFactory An {@link HlsDataSourceFactory} for {@link DataSource}s for manifests,
@@ -372,6 +374,7 @@ public final class HlsMediaSource extends BaseMediaSource
       ExoPlayer player,
       boolean isTopLevelSource,
       @Nullable TransferListener<? super DataSource> mediaTransferListener) {
+    this.mediaTransferListener = mediaTransferListener;
     EventDispatcher eventDispatcher = createEventDispatcher(/* mediaPeriodId= */ null);
     playlistTracker.start(manifestUri, eventDispatcher, /* listener= */ this);
   }
@@ -389,6 +392,7 @@ public final class HlsMediaSource extends BaseMediaSource
         extractorFactory,
         playlistTracker,
         dataSourceFactory,
+        mediaTransferListener,
         minLoadableRetryCount,
         eventDispatcher,
         allocator,

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

@@ -16,6 +16,7 @@
 package com.google.android.exoplayer2.source.smoothstreaming;
 
 import android.net.Uri;
+import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.SeekParameters;
@@ -35,6 +36,7 @@ import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
 import com.google.android.exoplayer2.upstream.LoaderErrorThrower;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
 import java.util.List;
@@ -53,10 +55,17 @@ public class DefaultSsChunkSource implements SsChunkSource {
     }
 
     @Override
-    public SsChunkSource createChunkSource(LoaderErrorThrower manifestLoaderErrorThrower,
+    public SsChunkSource createChunkSource(
-        SsManifest manifest, int elementIndex, TrackSelection trackSelection,
+        LoaderErrorThrower manifestLoaderErrorThrower,
-        TrackEncryptionBox[] trackEncryptionBoxes) {
+        SsManifest manifest,
+        int elementIndex,
+        TrackSelection trackSelection,
+        TrackEncryptionBox[] trackEncryptionBoxes,
+        @Nullable TransferListener<? super DataSource> transferListener) {
       DataSource dataSource = dataSourceFactory.createDataSource();
+      if (transferListener != null) {
+        dataSource.addTransferListener(transferListener);
+      }
       return new DefaultSsChunkSource(manifestLoaderErrorThrower, manifest, elementIndex,
           trackSelection, dataSource, trackEncryptionBoxes);
     }

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

@@ -15,11 +15,14 @@
  */
 package com.google.android.exoplayer2.source.smoothstreaming;
 
+import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.extractor.mp4.TrackEncryptionBox;
 import com.google.android.exoplayer2.source.chunk.ChunkSource;
 import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsManifest;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
+import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.LoaderErrorThrower;
+import com.google.android.exoplayer2.upstream.TransferListener;
 
 /**
  * A {@link ChunkSource} for SmoothStreaming.
@@ -37,6 +40,8 @@ public interface SsChunkSource extends ChunkSource {
      * @param streamElementIndex The index of the corresponding stream element in the manifest.
      * @param trackSelection The track selection.
      * @param trackEncryptionBoxes Track encryption boxes for the stream.
+     * @param transferListener The transfer listener which should be informed of any data transfers.
+     *     May be null if no listener is available.
      * @return The created {@link SsChunkSource}.
      */
     SsChunkSource createChunkSource(
@@ -44,7 +49,8 @@ public interface SsChunkSource extends ChunkSource {
         SsManifest manifest,
         int streamElementIndex,
         TrackSelection trackSelection,
-        TrackEncryptionBox[] trackEncryptionBoxes);
+        TrackEncryptionBox[] trackEncryptionBoxes,
+        @Nullable TransferListener<? super DataSource> transferListener);
   }
 
   /**

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

@@ -32,7 +32,9 @@ import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsManifest;
 import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsManifest.ProtectionElement;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.upstream.Allocator;
+import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.LoaderErrorThrower;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import java.io.IOException;
 import java.util.ArrayList;
 
@@ -45,6 +47,7 @@ import java.util.ArrayList;
   private static final int INITIALIZATION_VECTOR_SIZE = 8;
 
   private final SsChunkSource.Factory chunkSourceFactory;
+  private final @Nullable TransferListener<? super DataSource> transferListener;
   private final LoaderErrorThrower manifestLoaderErrorThrower;
   private final int minLoadableRetryCount;
   private final EventDispatcher eventDispatcher;
@@ -59,11 +62,17 @@ import java.util.ArrayList;
   private SequenceableLoader compositeSequenceableLoader;
   private boolean notifiedReadingStarted;
 
-  public SsMediaPeriod(SsManifest manifest, SsChunkSource.Factory chunkSourceFactory,
+  public SsMediaPeriod(
+      SsManifest manifest,
+      SsChunkSource.Factory chunkSourceFactory,
+      @Nullable TransferListener<? super DataSource> transferListener,
       CompositeSequenceableLoaderFactory compositeSequenceableLoaderFactory,
-      int minLoadableRetryCount, EventDispatcher eventDispatcher,
+      int minLoadableRetryCount,
-      LoaderErrorThrower manifestLoaderErrorThrower, Allocator allocator) {
+      EventDispatcher eventDispatcher,
+      LoaderErrorThrower manifestLoaderErrorThrower,
+      Allocator allocator) {
     this.chunkSourceFactory = chunkSourceFactory;
+    this.transferListener = transferListener;
     this.manifestLoaderErrorThrower = manifestLoaderErrorThrower;
     this.minLoadableRetryCount = minLoadableRetryCount;
     this.eventDispatcher = eventDispatcher;
@@ -214,8 +223,14 @@ import java.util.ArrayList;
   private ChunkSampleStream<SsChunkSource> buildSampleStream(TrackSelection selection,
       long positionUs) {
     int streamElementIndex = trackGroups.indexOf(selection.getTrackGroup());
-    SsChunkSource chunkSource = chunkSourceFactory.createChunkSource(manifestLoaderErrorThrower,
+    SsChunkSource chunkSource =
-        manifest, streamElementIndex, selection, trackEncryptionBoxes);
+        chunkSourceFactory.createChunkSource(
+            manifestLoaderErrorThrower,
+            manifest,
+            streamElementIndex,
+            selection,
+            trackEncryptionBoxes,
+            transferListener);
     return new ChunkSampleStream<>(
         manifest.streamElements[streamElementIndex].type,
         null,

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

@@ -285,6 +285,7 @@ public final class SsMediaSource extends BaseMediaSource
   private DataSource manifestDataSource;
   private Loader manifestLoader;
   private LoaderErrorThrower manifestLoaderErrorThrower;
+  private @Nullable TransferListener<? super DataSource> mediaTransferListener;
 
   private long manifestLoadStartTimestamp;
   private SsManifest manifest;
@@ -467,6 +468,7 @@ public final class SsMediaSource extends BaseMediaSource
       ExoPlayer player,
       boolean isTopLevelSource,
       @Nullable TransferListener<? super DataSource> mediaTransferListener) {
+    this.mediaTransferListener = mediaTransferListener;
     if (sideloadedManifest) {
       manifestLoaderErrorThrower = new LoaderErrorThrower.Dummy();
       processManifest();
@@ -488,9 +490,16 @@ public final class SsMediaSource extends BaseMediaSource
   public MediaPeriod createPeriod(MediaPeriodId id, Allocator allocator) {
     Assertions.checkArgument(id.periodIndex == 0);
     EventDispatcher eventDispatcher = createEventDispatcher(id);
-    SsMediaPeriod period = new SsMediaPeriod(manifest, chunkSourceFactory,
+    SsMediaPeriod period =
-        compositeSequenceableLoaderFactory, minLoadableRetryCount, eventDispatcher,
+        new SsMediaPeriod(
-        manifestLoaderErrorThrower, allocator);
+            manifest,
+            chunkSourceFactory,
+            mediaTransferListener,
+            compositeSequenceableLoaderFactory,
+            minLoadableRetryCount,
+            eventDispatcher,
+            manifestLoaderErrorThrower,
+            allocator);
     mediaPeriods.add(period);
     return period;
   }

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

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer2.testutil;
 
+import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.source.CompositeSequenceableLoader;
 import com.google.android.exoplayer2.source.MediaPeriod;
 import com.google.android.exoplayer2.source.MediaSourceEventListener.EventDispatcher;
@@ -24,6 +25,8 @@ import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.source.chunk.ChunkSampleStream;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 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.MimeTypes;
 import java.util.ArrayList;
 import java.util.List;
@@ -37,6 +40,7 @@ public class FakeAdaptiveMediaPeriod extends FakeMediaPeriod
 
   private final Allocator allocator;
   private final FakeChunkSource.Factory chunkSourceFactory;
+  private final @Nullable TransferListener<? super DataSource> transferListener;
   private final long durationUs;
 
   private Callback callback;
@@ -48,10 +52,12 @@ public class FakeAdaptiveMediaPeriod extends FakeMediaPeriod
       EventDispatcher eventDispatcher,
       Allocator allocator,
       FakeChunkSource.Factory chunkSourceFactory,
-      long durationUs) {
+      long durationUs,
+      @Nullable TransferListener<? super DataSource> transferListener) {
     super(trackGroupArray, eventDispatcher);
     this.allocator = allocator;
     this.chunkSourceFactory = chunkSourceFactory;
+    this.transferListener = transferListener;
     this.durationUs = durationUs;
     this.sampleStreams = newSampleStreamArray(0);
   }
@@ -128,7 +134,8 @@ public class FakeAdaptiveMediaPeriod extends FakeMediaPeriod
 
   @Override
   protected SampleStream createSampleStream(TrackSelection trackSelection) {
-    FakeChunkSource chunkSource = chunkSourceFactory.createChunkSource(trackSelection, durationUs);
+    FakeChunkSource chunkSource =
+        chunkSourceFactory.createChunkSource(trackSelection, durationUs, transferListener);
     return new ChunkSampleStream<>(
         MimeTypes.getTrackType(trackSelection.getSelectedFormat().sampleMimeType),
         null,

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

@@ -16,6 +16,7 @@
 package com.google.android.exoplayer2.testutil;
 
 import android.os.Handler;
+import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.Timeline.Period;
 import com.google.android.exoplayer2.source.MediaSource;
@@ -23,6 +24,8 @@ import com.google.android.exoplayer2.source.MediaSourceEventListener;
 import com.google.android.exoplayer2.source.MediaSourceEventListener.EventDispatcher;
 import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.upstream.Allocator;
+import com.google.android.exoplayer2.upstream.DataSource;
+import com.google.android.exoplayer2.upstream.TransferListener;
 
 /**
  * Fake {@link MediaSource} that provides a given timeline. Creating the period returns a
@@ -49,10 +52,16 @@ public class FakeAdaptiveMediaSource extends FakeMediaSource {
       MediaPeriodId id,
       TrackGroupArray trackGroupArray,
       Allocator allocator,
-      EventDispatcher eventDispatcher) {
+      EventDispatcher eventDispatcher,
+      @Nullable TransferListener<? super DataSource> transferListener) {
     Period period = timeline.getPeriod(id.periodIndex, new Period());
     return new FakeAdaptiveMediaPeriod(
-        trackGroupArray, eventDispatcher, allocator, chunkSourceFactory, period.durationUs);
+        trackGroupArray,
+        eventDispatcher,
+        allocator,
+        chunkSourceFactory,
+        period.durationUs,
+        transferListener);
   }
 
 }

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

@@ -16,6 +16,7 @@
 package com.google.android.exoplayer2.testutil;
 
 import android.net.Uri;
+import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.SeekParameters;
@@ -28,6 +29,7 @@ import com.google.android.exoplayer2.testutil.FakeDataSet.FakeData.Segment;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 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.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
@@ -52,11 +54,17 @@ public final class FakeChunkSource implements ChunkSource {
       this.dataSourceFactory = dataSourceFactory;
     }
 
-    public FakeChunkSource createChunkSource(TrackSelection trackSelection, long durationUs) {
+    public FakeChunkSource createChunkSource(
+        TrackSelection trackSelection,
+        long durationUs,
+        @Nullable TransferListener<? super DataSource> transferListener) {
       FakeAdaptiveDataSet dataSet =
           dataSetFactory.createDataSet(trackSelection.getTrackGroup(), durationUs);
       dataSourceFactory.setFakeDataSet(dataSet);
       DataSource dataSource = dataSourceFactory.createDataSource();
+      if (transferListener != null) {
+        dataSource.addTransferListener(transferListener);
+      }
       return new FakeChunkSource(trackSelection, dataSource, dataSet);
     }
 

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

@@ -61,6 +61,7 @@ public class FakeMediaSource extends BaseMediaSource {
   private boolean preparedSource;
   private boolean releasedSource;
   private Handler sourceInfoRefreshHandler;
+  private @Nullable TransferListener<? super DataSource> transferListener;
 
   /**
    * Creates a {@link FakeMediaSource}. This media source creates {@link FakeMediaPeriod}s with a
@@ -93,6 +94,7 @@ public class FakeMediaSource extends BaseMediaSource {
       boolean isTopLevelSource,
       @Nullable TransferListener<? super DataSource> mediaTransferListener) {
     assertThat(preparedSource).isFalse();
+    transferListener = mediaTransferListener;
     preparedSource = true;
     releasedSource = false;
     sourceInfoRefreshHandler = new Handler();
@@ -115,7 +117,7 @@ public class FakeMediaSource extends BaseMediaSource {
     EventDispatcher eventDispatcher =
         createEventDispatcher(period.windowIndex, id, period.getPositionInWindowMs());
     FakeMediaPeriod mediaPeriod =
-        createFakeMediaPeriod(id, trackGroupArray, allocator, eventDispatcher);
+        createFakeMediaPeriod(id, trackGroupArray, allocator, eventDispatcher, transferListener);
     activeMediaPeriods.add(mediaPeriod);
     createdMediaPeriods.add(id);
     return mediaPeriod;
@@ -195,13 +197,16 @@ public class FakeMediaSource extends BaseMediaSource {
    * @param trackGroupArray The {@link TrackGroupArray} supported by the media period.
    * @param allocator An {@link Allocator} from which to obtain media buffer allocations.
    * @param eventDispatcher An {@link EventDispatcher} to dispatch media source events.
+   * @param transferListener The transfer listener which should be informed of any data transfers.
+   *     May be null if no listener is available.
    * @return A new {@link FakeMediaPeriod}.
    */
   protected FakeMediaPeriod createFakeMediaPeriod(
       MediaPeriodId id,
       TrackGroupArray trackGroupArray,
       Allocator allocator,
-      EventDispatcher eventDispatcher) {
+      EventDispatcher eventDispatcher,
+      @Nullable TransferListener<? super DataSource> transferListener) {
     return new FakeMediaPeriod(trackGroupArray, eventDispatcher);
   }