Remove opt-out for suppressing wrong thread usage error.

Enforcing the correct thread usage has been enabled since 2.13.0.
Opting-out of this enforement is dangerous as it can hide very hard
to debug bugs.

PiperOrigin-RevId: 424815808

RELEASENOTES.md

@@ -148,6 +148,8 @@
         `MediaItem.LiveConfiguration.Builder#setTargetOffsetMs` to override the
         manifest, or `DashMediaSource#setFallbackTargetLiveOffsetMs` to provide
         a fallback value.
+    *   Remove `(Simple)ExoPlayer.setThrowsWhenUsingWrongThread`. Opting out of
+        the thread enforcement is no longer possible.
 
 ### 2.16.1 (2021-11-18)
 

docs/hello-world.md

@@ -119,11 +119,7 @@ which the player must be accessed can be queried using
 If you see `IllegalStateException` being thrown with the message "Player is
 accessed on the wrong thread", then some code in your app is accessing an
 `ExoPlayer` instance on the wrong thread (the exception's stack trace shows you
-where). You can temporarily opt out from these exceptions being thrown by
-calling `ExoPlayer.setThrowsWhenUsingWrongThread(false)`, in which case the
-issue will be logged as a warning instead. Using this opt out is not safe and
-may result in unexpected or obscure errors. It will be removed in ExoPlayer
-2.16.
+where).
 {:.info}
 
 For more information about ExoPlayer's threading model, see the

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayer.java

@@ -1456,19 +1456,6 @@ public interface ExoPlayer extends Player {
    */
   void setPriorityTaskManager(@Nullable PriorityTaskManager priorityTaskManager);
 
-  /**
-   * Sets whether the player should throw an {@link IllegalStateException} when methods are called
-   * from a thread other than the one associated with {@link #getApplicationLooper()}.
-   *
-   * <p>The default is {@code true} and this method will be removed in the future.
-   *
-   * @param throwsWhenUsingWrongThread Whether to throw when methods are called from a wrong thread.
-   * @deprecated Disabling the enforcement can result in hard-to-detect bugs. Do not use this method
-   *     except to ease the transition while wrong thread access problems are fixed.
-   */
-  @Deprecated
-  void setThrowsWhenUsingWrongThread(boolean throwsWhenUsingWrongThread);
-
   /**
    * Sets whether audio offload scheduling is enabled. If enabled, ExoPlayer's main loop will run as
    * rarely as possible when playing an audio stream using audio offload.

library/core/src/main/java/com/google/android/exoplayer2/SimpleExoPlayer.java

@@ -1541,9 +1541,7 @@ public class SimpleExoPlayer extends BasePlayer
     streamVolumeManager.setMuted(muted);
   }
 
-  @Deprecated
-  @Override
-  public void setThrowsWhenUsingWrongThread(boolean throwsWhenUsingWrongThread) {
+  /* package */ void setThrowsWhenUsingWrongThread(boolean throwsWhenUsingWrongThread) {
     this.throwsWhenUsingWrongThread = throwsWhenUsingWrongThread;
   }
 

testutils/src/main/java/com/google/android/exoplayer2/testutil/StubExoPlayer.java

@@ -357,12 +357,6 @@ public class StubExoPlayer extends StubPlayer implements ExoPlayer {
     throw new UnsupportedOperationException();
   }
 
-  @Deprecated
-  @Override
-  public void setThrowsWhenUsingWrongThread(boolean throwsWhenUsingWrongThread) {
-    throw new UnsupportedOperationException();
-  }
-
   @Override
   public void experimentalSetOffloadSchedulingEnabled(boolean offloadSchedulingEnabled) {
     throw new UnsupportedOperationException();