Make SelectionOverride parcelable

Issue: #3915

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=193494016

library/core/src/main/java/com/google/android/exoplayer2/trackselection/DefaultTrackSelector.java

@@ -37,6 +37,7 @@ import com.google.android.exoplayer2.upstream.BandwidthMeter;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -630,7 +631,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
   }
 
   /** A track selection override. */
-  public static class SelectionOverride {
+  public static final class SelectionOverride implements Parcelable {
 
     public final int groupIndex;
     public final int[] tracks;
@@ -646,6 +647,13 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       this.length = tracks.length;
     }
 
+    /* package */ SelectionOverride(Parcel in) {
+      groupIndex = in.readInt();
+      length = in.readByte();
+      tracks = new int[length];
+      in.readIntArray(tracks);
+    }
+
     /** Returns whether this override contains the specified track index. */
     public boolean containsTrack(int track) {
       for (int overrideTrack : tracks) {
@@ -655,6 +663,51 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       }
       return false;
     }
+
+    @Override
+    public int hashCode() {
+      return 31 * groupIndex + Arrays.hashCode(tracks);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+      if (this == obj) {
+        return true;
+      }
+      if (obj == null || getClass() != obj.getClass()) {
+        return false;
+      }
+      SelectionOverride other = (SelectionOverride) obj;
+      return groupIndex == other.groupIndex && Arrays.equals(tracks, other.tracks);
+    }
+
+    // Parcelable implementation.
+
+    @Override
+    public int describeContents() {
+      return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+      dest.writeInt(groupIndex);
+      dest.writeInt(tracks.length);
+      dest.writeIntArray(tracks);
+    }
+
+    public static final Parcelable.Creator<SelectionOverride> CREATOR =
+        new Parcelable.Creator<SelectionOverride>() {
+
+          @Override
+          public SelectionOverride createFromParcel(Parcel in) {
+            return new SelectionOverride(in);
+          }
+
+          @Override
+          public SelectionOverride[] newArray(int size) {
+            return new SelectionOverride[size];
+          }
+        };
   }
 
   /**

library/core/src/test/java/com/google/android/exoplayer2/trackselection/DefaultTrackSelectorTest.java

@@ -34,6 +34,7 @@ import com.google.android.exoplayer2.source.TrackGroup;
 import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.trackselection.DefaultTrackSelector.Parameters;
 import com.google.android.exoplayer2.trackselection.DefaultTrackSelector.ParametersBuilder;
+import com.google.android.exoplayer2.trackselection.DefaultTrackSelector.SelectionOverride;
 import com.google.android.exoplayer2.trackselection.TrackSelector.InvalidationListener;
 import com.google.android.exoplayer2.util.MimeTypes;
 import java.util.HashMap;
@@ -147,6 +148,24 @@ public final class DefaultTrackSelectorTest {
     parcel.recycle();
   }
 
+  /** Tests {@link SelectionOverride}'s {@link android.os.Parcelable} implementation. */
+  @Test
+  public void testSelectionOverrideParcelable() {
+    int[] tracks = new int[] {2, 3};
+    SelectionOverride selectionOverrideToParcel =
+        new SelectionOverride(/* groupIndex= */ 1, tracks);
+
+    Parcel parcel = Parcel.obtain();
+    selectionOverrideToParcel.writeToParcel(parcel, 0);
+    parcel.setDataPosition(0);
+
+    SelectionOverride selectionOverrideFromParcel =
+        SelectionOverride.CREATOR.createFromParcel(parcel);
+    assertThat(selectionOverrideFromParcel).isEqualTo(selectionOverrideToParcel);
+
+    parcel.recycle();
+  }
+
   /** Tests that a null override clears a track selection. */
   @Test
   public void testSelectTracksWithNullOverride() throws ExoPlaybackException {