Disable chronometer for playback speeds != 1.0

This doesn't work because the Chronometer text layout can only count in realtime.

Issue:#6816
PiperOrigin-RevId: 288711702

RELEASENOTES.md

@@ -54,6 +54,8 @@
 * OkHttp extension: Upgrade OkHttp dependency to 3.12.7, which fixes a class of
   `SocketTimeoutException` issues when using HTTP/2
   ([#4078](https://github.com/google/ExoPlayer/issues/4078)).
+* Don't use notification chronometer if playback speed is != 1.0
+  ([#6816](https://github.com/google/ExoPlayer/issues/6816)).
 
 ### 2.11.1 (2019-12-20) ###
 

library/ui/src/main/java/com/google/android/exoplayer2/ui/PlayerNotificationManager.java

@@ -927,7 +927,18 @@ public final void setSmallIcon(@DrawableRes int smallIconResourceId) {
   }
 
   /**
-   * Sets whether the elapsed time of the media playback should be displayed
+   * Sets whether the elapsed time of the media playback should be displayed.
+   *
+   * <p>Note that this setting only works if all of the following are true:
+   *
+   * <ul>
+   *   <li>The media is {@link Player#isPlaying() actively playing}.
+   *   <li>The media is not {@link Player#isCurrentWindowDynamic() dynamically changing its
+   *       duration} (like for example a live stream).
+   *   <li>The media is not {@link Player#isPlayingAd() interrupted by an ad}.
+   *   <li>The media is played at {@link Player#getPlaybackParameters() regular speed}.
+   *   <li>The device is running at least API 21 (Lollipop).
+   * </ul>
    *
    * <p>See {@link NotificationCompat.Builder#setUsesChronometer(boolean)}.
    *
@@ -1082,7 +1093,8 @@ protected NotificationCompat.Builder createNotification(
         && useChronometer
         && player.isPlaying()
         && !player.isPlayingAd()
-        && !player.isCurrentWindowDynamic()) {
+        && !player.isCurrentWindowDynamic()
+        && player.getPlaybackParameters().speed == 1f) {
       builder
           .setWhen(System.currentTimeMillis() - player.getContentPosition())
           .setShowWhen(true)