Add set/getShuffleModeEnabled to Player interface.

And implement a basic version of the methods in all implementations.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=166041342

extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/CastPlayer.java

@@ -331,6 +331,17 @@ public final class CastPlayer implements Player {
   }
 
   @Override
+  public void setShuffleModeEnabled(boolean shuffleModeEnabled) {
+    // TODO: Support shuffle mode.
+  }
+
+  @Override
+  public boolean getShuffleModeEnabled() {
+    // TODO: Support shuffle mode.
+    return false;
+  }
+
+  @Override
   public TrackSelectionArray getCurrentTrackSelections() {
     return currentTrackSelection;
   }

library/core/src/androidTest/java/com/google/android/exoplayer2/source/DynamicConcatenatingMediaSourceTest.java

@@ -397,6 +397,16 @@ public final class DynamicConcatenatingMediaSourceTest extends TestCase {
     }
 
     @Override
+    public void setShuffleModeEnabled(boolean shuffleModeEnabled) {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean getShuffleModeEnabled() {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
     public boolean isLoading() {
       throw new UnsupportedOperationException();
     }

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

@@ -53,6 +53,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
   private boolean tracksSelected;
   private boolean playWhenReady;
   private @RepeatMode int repeatMode;
+  private boolean shuffleModeEnabled;
   private int playbackState;
   private int pendingSeekAcks;
   private int pendingPrepareAcks;
@@ -87,6 +88,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
     this.trackSelector = Assertions.checkNotNull(trackSelector);
     this.playWhenReady = false;
     this.repeatMode = Player.REPEAT_MODE_OFF;
+    this.shuffleModeEnabled = false;
     this.playbackState = Player.STATE_IDLE;
     this.listeners = new CopyOnWriteArraySet<>();
     emptyTrackSelections = new TrackSelectionArray(new TrackSelection[renderers.length]);
@@ -190,6 +192,18 @@ import java.util.concurrent.CopyOnWriteArraySet;
   }
 
   @Override
+  public void setShuffleModeEnabled(boolean shuffleModeEnabled) {
+    if (this.shuffleModeEnabled != shuffleModeEnabled) {
+      this.shuffleModeEnabled = shuffleModeEnabled;
+    }
+  }
+
+  @Override
+  public boolean getShuffleModeEnabled() {
+    return shuffleModeEnabled;
+  }
+
+  @Override
   public boolean isLoading() {
     return isLoading;
   }

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

@@ -220,6 +220,18 @@ public interface Player {
   @RepeatMode int getRepeatMode();
 
   /**
+   * Sets whether shuffling of windows is enabled.
+   *
+   * @param shuffleModeEnabled Whether shuffling is enabled.
+   */
+  void setShuffleModeEnabled(boolean shuffleModeEnabled);
+
+  /**
+   * Returns whether shuffling of windows is enabled.
+   */
+  boolean getShuffleModeEnabled();
+
+  /**
    * Whether the player is currently loading the source.
    *
    * @return Whether the player is currently loading the source.

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

@@ -643,6 +643,16 @@ public class SimpleExoPlayer implements ExoPlayer {
   }
 
   @Override
+  public void setShuffleModeEnabled(boolean shuffleModeEnabled) {
+    player.setShuffleModeEnabled(shuffleModeEnabled);
+  }
+
+  @Override
+  public boolean getShuffleModeEnabled() {
+    return player.getShuffleModeEnabled();
+  }
+
+  @Override
   public boolean isLoading() {
     return player.isLoading();
   }

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

@@ -155,6 +155,16 @@ public class FakeSimpleExoPlayer extends SimpleExoPlayer {
     }
 
     @Override
+    public void setShuffleModeEnabled(boolean shuffleModeEnabled) {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean getShuffleModeEnabled() {
+      return false;
+    }
+
+    @Override
     public boolean isLoading() {
       return isLoading;
     }