Add fake adaptive media source.

This class extends the existing FakeMediaSource by creating a
FakeAdaptiveMediaPeriod instead of a FakeMediaPeriod.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=162918487

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

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.testutil;
+
+import android.os.Handler;
+import com.google.android.exoplayer2.Timeline;
+import com.google.android.exoplayer2.Timeline.Period;
+import com.google.android.exoplayer2.source.AdaptiveMediaSourceEventListener;
+import com.google.android.exoplayer2.source.AdaptiveMediaSourceEventListener.EventDispatcher;
+import com.google.android.exoplayer2.source.MediaSource;
+import com.google.android.exoplayer2.source.TrackGroupArray;
+import com.google.android.exoplayer2.upstream.Allocator;
+
+/**
+ * Fake {@link MediaSource} that provides a given timeline. Creating the period returns a
+ * {@link FakeAdaptiveMediaPeriod} from the given {@link TrackGroupArray}.
+ */
+public class FakeAdaptiveMediaSource extends FakeMediaSource {
+
+  private final EventDispatcher eventDispatcher;
+  private final FakeChunkSource.Factory chunkSourceFactory;
+
+  public FakeAdaptiveMediaSource(Timeline timeline, Object manifest,
+      TrackGroupArray trackGroupArray, Handler eventHandler,
+      AdaptiveMediaSourceEventListener eventListener, FakeChunkSource.Factory chunkSourceFactory) {
+    super(timeline, manifest, trackGroupArray);
+    this.eventDispatcher = new EventDispatcher(eventHandler, eventListener);
+    this.chunkSourceFactory = chunkSourceFactory;
+  }
+
+  @Override
+  protected FakeMediaPeriod createFakeMediaPeriod(MediaPeriodId id, TrackGroupArray trackGroupArray,
+      Allocator allocator) {
+    Period period = timeline.getPeriod(id.periodIndex, new Period());
+    return new FakeAdaptiveMediaPeriod(trackGroupArray, eventDispatcher, allocator,
+        chunkSourceFactory, period.durationUs);
+  }
+
+}

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

@@ -34,7 +34,7 @@ import junit.framework.Assert;
  */
 public class FakeMediaSource implements MediaSource {
 
-  private final Timeline timeline;
+  protected final Timeline timeline;
   private final Object manifest;
   private final TrackGroupArray trackGroupArray;
   private final ArrayList<FakeMediaPeriod> activeMediaPeriods;
@@ -82,7 +82,7 @@ public class FakeMediaSource implements MediaSource {
     Assertions.checkIndex(id.periodIndex, 0, timeline.getPeriodCount());
     Assert.assertTrue(preparedSource);
     Assert.assertFalse(releasedSource);
-    FakeMediaPeriod mediaPeriod = new FakeMediaPeriod(trackGroupArray);
+    FakeMediaPeriod mediaPeriod = createFakeMediaPeriod(id, trackGroupArray, allocator);
     activeMediaPeriods.add(mediaPeriod);
     return mediaPeriod;
   }
@@ -104,6 +104,11 @@ public class FakeMediaSource implements MediaSource {
     releasedSource = true;
   }
 
+  protected FakeMediaPeriod createFakeMediaPeriod(MediaPeriodId id, TrackGroupArray trackGroupArray,
+      Allocator allocator) {
+    return new FakeMediaPeriod(trackGroupArray);
+  }
+
   private static TrackGroupArray buildTrackGroupArray(Format... formats) {
     TrackGroup[] trackGroups = new TrackGroup[formats.length];
     for (int i = 0; i < formats.length; i++) {