Refactor #6.HLS.1

1. Merge HlsOutput and HlsSampleSource -> HlsTrackStreamWrapper.
2. Rename HlsSource -> HlsSampleSource2. This will be renamed to
   HlsSampleSource in a subsequent CL.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=122415970

demo/src/main/java/com/google/android/exoplayer/demo/PlayerActivity.java

@@ -29,7 +29,7 @@
 import com.google.android.exoplayer.demo.ui.TrackSelectionHelper;
 import com.google.android.exoplayer.drm.UnsupportedDrmException;
 import com.google.android.exoplayer.extractor.ExtractorSampleSource;
-import com.google.android.exoplayer.hls.HlsSource;
+import com.google.android.exoplayer.hls.HlsSampleSource2;
 import com.google.android.exoplayer.metadata.id3.GeobFrame;
 import com.google.android.exoplayer.metadata.id3.Id3Frame;
 import com.google.android.exoplayer.metadata.id3.PrivFrame;
@@ -278,7 +278,7 @@ private SampleSource buildSource(Uri uri, String id, String provider, int type)
         return new DashSampleSource(uri, dataSourceFactory, player.getBandwidthMeter(),
             player.getMainHandler(), player);
       case Util.TYPE_HLS:
-        return new HlsSource(uri, dataSourceFactory, player.getBandwidthMeter(),
+        return new HlsSampleSource2(uri, dataSourceFactory, player.getBandwidthMeter(),
             player.getMainHandler(), player);
       case Util.TYPE_OTHER:
         Allocator allocator = new DefaultAllocator(C.DEFAULT_BUFFER_SEGMENT_SIZE);

library/src/main/java/com/google/android/exoplayer/hls/HlsChunkSource.java

@@ -461,7 +461,7 @@ public void getNextChunk(HlsMediaChunk previous, long playbackPositionUs, ChunkH
   }
 
   /**
-   * Invoked when the {@link HlsSampleSource} has finished loading a chunk obtained from this
+   * Invoked when the {@link HlsTrackStreamWrapper} has finished loading a chunk obtained from this
    * source.
    *
    * @param chunk The chunk whose load has been completed.
@@ -480,8 +480,8 @@ public void onChunkLoadCompleted(Chunk chunk) {
   }
 
   /**
-   * Invoked when the {@link HlsSampleSource} encounters an error loading a chunk obtained from
-   * this source.
+   * Invoked when the {@link HlsTrackStreamWrapper} encounters an error loading a chunk obtained
+   * from this source.
    *
    * @param chunk The chunk whose load encountered the error.
    * @param cancelable Whether the load can be canceled.

library/src/main/java/com/google/android/exoplayer/hls/HlsMediaChunk.java

@@ -59,9 +59,9 @@
    * @param discontinuitySequenceNumber The discontinuity sequence number of the chunk.
    * @param extractor The extractor to parse samples from the data.
    * @param extractorNeedsInit Whether the extractor needs initializing with the target
-   *     {@link HlsOutput}.
+   *     {@link HlsTrackStreamWrapper}.
    * @param shouldSpliceIn Whether the samples parsed from this chunk should be spliced into any
-   *     samples already queued to the {@link HlsOutput}.
+   *     samples already queued to the {@link HlsTrackStreamWrapper}.
    * @param encryptionKey For AES encryption chunks, the encryption key.
    * @param encryptionIv For AES encryption chunks, the encryption initialization vector.
    */
@@ -80,12 +80,12 @@ public HlsMediaChunk(DataSource dataSource, DataSpec dataSpec, int trigger, Form
   }
 
   /**
-   * Initializes the chunk for loading, setting the {@link HlsOutput} that will receive samples as
-   * they are loaded.
+   * Initializes the chunk for loading, setting the {@link HlsTrackStreamWrapper} that will receive
+   * samples as they are loaded.
    *
    * @param output The output that will receive the loaded samples.
    */
-  public void init(HlsOutput output) {
+  public void init(HlsTrackStreamWrapper output) {
     if (shouldSpliceIn) {
       output.splice();
     }