Avoid concurrent read/write access to sampleQueues in HlsSampleStreamWrapper

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=177435977

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

@@ -16,12 +16,15 @@
 package com.google.android.exoplayer2.source.hls;
 package com.google.android.exoplayer2.source.hls;
 
 
 import android.os.Handler;
 import android.os.Handler;
+import android.util.Log;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.FormatHolder;
 import com.google.android.exoplayer2.FormatHolder;
 import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
 import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
+import com.google.android.exoplayer2.extractor.DummyTrackOutput;
 import com.google.android.exoplayer2.extractor.ExtractorOutput;
 import com.google.android.exoplayer2.extractor.ExtractorOutput;
 import com.google.android.exoplayer2.extractor.SeekMap;
 import com.google.android.exoplayer2.extractor.SeekMap;
+import com.google.android.exoplayer2.extractor.TrackOutput;
 import com.google.android.exoplayer2.source.AdaptiveMediaSourceEventListener.EventDispatcher;
 import com.google.android.exoplayer2.source.AdaptiveMediaSourceEventListener.EventDispatcher;
 import com.google.android.exoplayer2.source.SampleQueue;
 import com.google.android.exoplayer2.source.SampleQueue;
 import com.google.android.exoplayer2.source.SampleQueue.UpstreamFormatChangedListener;
 import com.google.android.exoplayer2.source.SampleQueue.UpstreamFormatChangedListener;
@@ -67,6 +70,8 @@ import java.util.Arrays;
 
 
   }
   }
 
 
+  private static final String TAG = "HlsSampleStreamWrapper";
+
   private static final int PRIMARY_TYPE_NONE = 0;
   private static final int PRIMARY_TYPE_NONE = 0;
   private static final int PRIMARY_TYPE_TEXT = 1;
   private static final int PRIMARY_TYPE_TEXT = 1;
   private static final int PRIMARY_TYPE_AUDIO = 2;
   private static final int PRIMARY_TYPE_AUDIO = 2;
@@ -588,13 +593,17 @@ import java.util.Arrays;
   // ExtractorOutput implementation. Called by the loading thread.
   // ExtractorOutput implementation. Called by the loading thread.
 
 
   @Override
   @Override
-  public SampleQueue track(int id, int type) {
+  public TrackOutput track(int id, int type) {
     int trackCount = sampleQueues.length;
     int trackCount = sampleQueues.length;
     for (int i = 0; i < trackCount; i++) {
     for (int i = 0; i < trackCount; i++) {
       if (sampleQueueTrackIds[i] == id) {
       if (sampleQueueTrackIds[i] == id) {
         return sampleQueues[i];
         return sampleQueues[i];
       }
       }
     }
     }
+    if (sampleQueuesBuilt) {
+      Log.w(TAG, "Unmapped track with id " + id + " of type " + type);
+      return new DummyTrackOutput();
+    }
     SampleQueue trackOutput = new SampleQueue(allocator);
     SampleQueue trackOutput = new SampleQueue(allocator);
     trackOutput.setSampleOffsetUs(sampleOffsetUs);
     trackOutput.setSampleOffsetUs(sampleOffsetUs);
     trackOutput.setUpstreamFormatChangeListener(this);
     trackOutput.setUpstreamFormatChangeListener(this);