Fix handling of ad tags where ad groups are out of order

IMA's cue points may not be in order, so sort them. It looks like IMA events use
time ordered ad indices, so it is not necessary to map between the original cue
point order and the time order.

Issue: #3716

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=185495798

RELEASENOTES.md

@@ -88,6 +88,8 @@
     * Add support for playing non-Extractor content MediaSources in
     * Add support for playing non-Extractor content MediaSources in
       the IMA demo app
       the IMA demo app
       ([#3676](https://github.com/google/ExoPlayer/issues/3676)).
       ([#3676](https://github.com/google/ExoPlayer/issues/3676)).
+    * Fix handling of ad tags where ad groups are out of order
+      ([#3716](https://github.com/google/ExoPlayer/issues/3716)).
 * `EventLogger` moved from the demo app into the core library.
 * `EventLogger` moved from the demo app into the core library.
 * Fix ANR issue on Huawei P8 Lite
 * Fix ANR issue on Huawei P8 Lite
   ([#3724](https://github.com/google/ExoPlayer/issues/3724)).
   ([#3724](https://github.com/google/ExoPlayer/issues/3724)).

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

@@ -970,11 +970,17 @@ public final class ImaAdsLoader extends Player.DefaultEventListener implements A
 
 
     int count = cuePoints.size();
     int count = cuePoints.size();
     long[] adGroupTimesUs = new long[count];
     long[] adGroupTimesUs = new long[count];
+    int adGroupIndex = 0;
     for (int i = 0; i < count; i++) {
     for (int i = 0; i < count; i++) {
       double cuePoint = cuePoints.get(i);
       double cuePoint = cuePoints.get(i);
-      adGroupTimesUs[i] =
-          cuePoint == -1.0 ? C.TIME_END_OF_SOURCE : (long) (C.MICROS_PER_SECOND * cuePoint);
+      if (cuePoint == -1.0) {
+        adGroupTimesUs[count - 1] = C.TIME_END_OF_SOURCE;
+      } else {
+        adGroupTimesUs[adGroupIndex++] = (long) (C.MICROS_PER_SECOND * cuePoint);
+      }
     }
     }
+    // Cue points may be out of order, so sort them.
+    Arrays.sort(adGroupTimesUs, 0, adGroupIndex);
     return adGroupTimesUs;
     return adGroupTimesUs;
   }
   }