Support multiplexed fMP4.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117228173

library/src/main/java/com/google/android/exoplayer/extractor/ChunkIndex.java

@@ -50,20 +50,18 @@ public final class ChunkIndex implements SeekMap {
   private final long durationUs;
 
   /**
-   * @param durationUs The duration of the stream.
    * @param sizes The chunk sizes, in bytes.
    * @param offsets The chunk byte offsets.
    * @param durationsUs The chunk durations, in microseconds.
    * @param timesUs The start time of each chunk, in microseconds.
    */
-  public ChunkIndex(long durationUs, int[] sizes, long[] offsets, long[] durationsUs,
-      long[] timesUs) {
-    this.durationUs = durationUs;
+  public ChunkIndex(int[] sizes, long[] offsets, long[] durationsUs, long[] timesUs) {
     this.sizes = sizes;
     this.offsets = offsets;
     this.durationsUs = durationsUs;
     this.timesUs = timesUs;
     length = sizes.length;
+    durationUs = durationsUs[length - 1] + timesUs[length - 1];
   }
 
   /**

library/src/main/java/com/google/android/exoplayer/smoothstreaming/SmoothStreamingChunkSource.java

@@ -338,9 +338,8 @@ public class SmoothStreamingChunkSource implements ChunkSource {
             Track track = new Track(j, streamElementType, timescale, C.UNKNOWN_TIME_US, durationUs,
                 formats[j], trackEncryptionBoxes, nalUnitLengthFieldLength, null, null);
             FragmentedMp4Extractor extractor = new FragmentedMp4Extractor(
-                FragmentedMp4Extractor.WORKAROUND_EVERY_VIDEO_FRAME_IS_SYNC_FRAME
-                | FragmentedMp4Extractor.WORKAROUND_IGNORE_TFDT_BOX);
-            extractor.setTrack(track);
+                FragmentedMp4Extractor.FLAG_WORKAROUND_EVERY_VIDEO_FRAME_IS_SYNC_FRAME
+                | FragmentedMp4Extractor.FLAG_WORKAROUND_IGNORE_TFDT_BOX, track);
             extractorWrappers[j] = new ChunkExtractorWrapper(extractor);
           }
           elementIndex = i;