Move extractTimelineFromMediaSource to test util class.

This also ensures that TimelineAsserts only contains assert methods.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=160827271

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

@@ -24,6 +24,7 @@ import com.google.android.exoplayer2.Timeline.Window;
 import com.google.android.exoplayer2.testutil.FakeMediaSource;
 import com.google.android.exoplayer2.testutil.FakeTimeline;
 import com.google.android.exoplayer2.testutil.FakeTimeline.TimelineWindowDefinition;
+import com.google.android.exoplayer2.testutil.TestUtil;
 import com.google.android.exoplayer2.testutil.TimelineAsserts;
 
 /**
@@ -123,7 +124,7 @@ public final class ClippingMediaSourceTest extends InstrumentationTestCase {
    */
   private static Timeline getClippedTimeline(Timeline timeline, long startMs, long endMs) {
     MediaSource mediaSource = new FakeMediaSource(timeline, null);
-    return TimelineAsserts.extractTimelineFromMediaSource(
+    return TestUtil.extractTimelineFromMediaSource(
         new ClippingMediaSource(mediaSource, startMs, endMs));
   }
 

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

@@ -21,6 +21,7 @@ import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.testutil.FakeMediaSource;
 import com.google.android.exoplayer2.testutil.FakeTimeline;
 import com.google.android.exoplayer2.testutil.FakeTimeline.TimelineWindowDefinition;
+import com.google.android.exoplayer2.testutil.TestUtil;
 import com.google.android.exoplayer2.testutil.TimelineAsserts;
 import junit.framework.TestCase;
 
@@ -105,7 +106,7 @@ public final class ConcatenatingMediaSourceTest extends TestCase {
     for (int i = 0; i < timelines.length; i++) {
       mediaSources[i] = new FakeMediaSource(timelines[i], null);
     }
-    return TimelineAsserts.extractTimelineFromMediaSource(
+    return TestUtil.extractTimelineFromMediaSource(
         new ConcatenatingMediaSource(isRepeatOneAtomic, mediaSources));
   }
 

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

@@ -21,6 +21,7 @@ import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.testutil.FakeMediaSource;
 import com.google.android.exoplayer2.testutil.FakeTimeline;
 import com.google.android.exoplayer2.testutil.FakeTimeline.TimelineWindowDefinition;
+import com.google.android.exoplayer2.testutil.TestUtil;
 import com.google.android.exoplayer2.testutil.TimelineAsserts;
 import junit.framework.TestCase;
 
@@ -32,7 +33,7 @@ public class LoopingMediaSourceTest extends TestCase {
   private final Timeline multiWindowTimeline;
 
   public LoopingMediaSourceTest() {
-    multiWindowTimeline = TimelineAsserts.extractTimelineFromMediaSource(new FakeMediaSource(
+    multiWindowTimeline = TestUtil.extractTimelineFromMediaSource(new FakeMediaSource(
         new FakeTimeline(new TimelineWindowDefinition(1, 111),
             new TimelineWindowDefinition(1, 222), new TimelineWindowDefinition(1, 333)), null));
   }
@@ -87,7 +88,7 @@ public class LoopingMediaSourceTest extends TestCase {
    */
   private static Timeline getLoopingTimeline(Timeline timeline, int loopCount) {
     MediaSource mediaSource = new FakeMediaSource(timeline, null);
-    return TimelineAsserts.extractTimelineFromMediaSource(
+    return TestUtil.extractTimelineFromMediaSource(
         new LoopingMediaSource(mediaSource, loopCount));
   }
 

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

@@ -19,9 +19,12 @@ import android.app.Instrumentation;
 import android.test.InstrumentationTestCase;
 import android.test.MoreAsserts;
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.extractor.Extractor;
 import com.google.android.exoplayer2.extractor.PositionHolder;
 import com.google.android.exoplayer2.extractor.SeekMap;
+import com.google.android.exoplayer2.source.MediaSource;
+import com.google.android.exoplayer2.source.MediaSource.Listener;
 import com.google.android.exoplayer2.testutil.FakeExtractorInput.SimulatedIOException;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
@@ -219,6 +222,32 @@ public class TestUtil {
   }
 
   /**
+   * Extracts the timeline from a media source.
+   */
+  public static Timeline extractTimelineFromMediaSource(MediaSource mediaSource) {
+    class TimelineListener implements Listener {
+      private Timeline timeline;
+      @Override
+      public synchronized void onSourceInfoRefreshed(Timeline timeline, Object manifest) {
+        this.timeline = timeline;
+        this.notify();
+      }
+    }
+    TimelineListener listener = new TimelineListener();
+    mediaSource.prepareSource(null, true, listener);
+    synchronized (listener) {
+      while (listener.timeline == null) {
+        try {
+          listener.wait();
+        } catch (InterruptedException e) {
+          Assert.fail(e.getMessage());
+        }
+      }
+    }
+    return listener.timeline;
+  }
+
+  /**
    * Calls {@link #assertOutput(Extractor, String, byte[], Instrumentation, boolean, boolean,
    * boolean)} with all possible combinations of "simulate" parameters.
    *

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

@@ -22,8 +22,6 @@ import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.Timeline.Period;
 import com.google.android.exoplayer2.Timeline.Window;
-import com.google.android.exoplayer2.source.MediaSource;
-import com.google.android.exoplayer2.source.MediaSource.Listener;
 
 /**
  * Unit test for {@link Timeline}.
@@ -33,22 +31,6 @@ public final class TimelineAsserts {
   private TimelineAsserts() {}
 
   /**
-   * Extracts the timeline from a media source.
-   */
-  public static Timeline extractTimelineFromMediaSource(MediaSource mediaSource) {
-    class TimelineListener implements Listener {
-      private Timeline timeline;
-      @Override
-      public void onSourceInfoRefreshed(Timeline timeline, Object manifest) {
-        this.timeline = timeline;
-      }
-    }
-    TimelineListener listener = new TimelineListener();
-    mediaSource.prepareSource(null, true, listener);
-    return listener.timeline;
-  }
-
-  /**
    * Assert that timeline is empty (i.e. has no windows or periods).
    */
   public static void assertEmpty(Timeline timeline) {