TestUtil.assertOutput() uses ExtractorFactory to create a new instance of the…

TestUtil.assertOutput() uses ExtractorFactory to create a new instance of the Extractor for each combination of simulation parameters.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=123506162

library/src/androidTest/java/com/google/android/exoplayer/extractor/ogg/OggExtractorFileTests.java

@@ -15,7 +15,9 @@
  */
 package com.google.android.exoplayer.extractor.ogg;
 
+import com.google.android.exoplayer.extractor.Extractor;
 import com.google.android.exoplayer.testutil.TestUtil;
+import com.google.android.exoplayer.testutil.TestUtil.ExtractorFactory;
 
 import android.test.InstrumentationTestCase;
 
@@ -24,21 +26,28 @@ import android.test.InstrumentationTestCase;
  */
 public final class OggExtractorFileTests extends InstrumentationTestCase {
 
+  private static final ExtractorFactory OGG_EXTRACTOR_FACTORY = new ExtractorFactory() {
+    @Override
+    public Extractor create() {
+      return new OggExtractor();
+    }
+  };
+
   public void testOpus() throws Exception {
-    TestUtil.assertOutput(new OggExtractor(), "ogg/bear.opus", getInstrumentation());
+    TestUtil.assertOutput(OGG_EXTRACTOR_FACTORY, "ogg/bear.opus", getInstrumentation());
   }
 
   public void testFlac() throws Exception {
-    TestUtil.assertOutput(new OggExtractor(), "ogg/bear_flac.ogg", getInstrumentation());
+    TestUtil.assertOutput(OGG_EXTRACTOR_FACTORY, "ogg/bear_flac.ogg", getInstrumentation());
   }
 
   public void testFlacNoSeektable() throws Exception {
-    TestUtil.assertOutput(new OggExtractor(), "ogg/bear_flac_noseektable.ogg",
+    TestUtil.assertOutput(OGG_EXTRACTOR_FACTORY, "ogg/bear_flac_noseektable.ogg",
         getInstrumentation());
   }
 
   public void testVorbis() throws Exception {
-    TestUtil.assertOutput(new OggExtractor(), "ogg/bear_vorbis.ogg", getInstrumentation());
+    TestUtil.assertOutput(OGG_EXTRACTOR_FACTORY, "ogg/bear_vorbis.ogg", getInstrumentation());
   }
 
 }

library/src/androidTest/java/com/google/android/exoplayer/testutil/TestUtil.java

@@ -36,6 +36,13 @@ import java.util.Random;
  */
 public class TestUtil {
 
+  /**
+   * A factory for {@link Extractor} instances.
+   */
+  public interface ExtractorFactory {
+    Extractor create();
+  }
+
   private static final String DUMP_EXTENSION = ".dump";
   private static final String UNKNOWN_LENGTH_EXTENSION = ".unklen";
 
@@ -170,23 +177,24 @@ public class TestUtil {
    * Calls {@link #assertOutput(Extractor, String, Instrumentation, boolean, boolean, boolean)} with
    * all possible combinations of "simulate" parameters.
    *
-   * @param extractor The {@link Extractor} to be tested.
+   * @param factory An {@link ExtractorFactory} which creates instances of the {@link Extractor}
+   *     class which is to be tested.
    * @param sampleFile The path to the input sample.
    * @param instrumentation To be used to load the sample file.
    * @throws IOException If reading from the input fails.
    * @throws InterruptedException If interrupted while reading from the input.
    * @see #assertOutput(Extractor, String, Instrumentation, boolean, boolean, boolean)
    */
-  public static void assertOutput(Extractor extractor, String sampleFile,
+  public static void assertOutput(ExtractorFactory factory, String sampleFile,
       Instrumentation instrumentation) throws IOException, InterruptedException {
-    assertOutput(extractor, sampleFile, instrumentation, false, false, false);
-    assertOutput(extractor, sampleFile, instrumentation,  true, false, false);
-    assertOutput(extractor, sampleFile, instrumentation, false,  true, false);
-    assertOutput(extractor, sampleFile, instrumentation,  true,  true, false);
-    assertOutput(extractor, sampleFile, instrumentation, false, false,  true);
-    assertOutput(extractor, sampleFile, instrumentation,  true, false,  true);
-    assertOutput(extractor, sampleFile, instrumentation, false,  true,  true);
-    assertOutput(extractor, sampleFile, instrumentation,  true,  true,  true);
+    assertOutput(factory.create(), sampleFile, instrumentation, false, false, false);
+    assertOutput(factory.create(), sampleFile, instrumentation,  true, false, false);
+    assertOutput(factory.create(), sampleFile, instrumentation, false,  true, false);
+    assertOutput(factory.create(), sampleFile, instrumentation,  true,  true, false);
+    assertOutput(factory.create(), sampleFile, instrumentation, false, false,  true);
+    assertOutput(factory.create(), sampleFile, instrumentation,  true, false,  true);
+    assertOutput(factory.create(), sampleFile, instrumentation, false,  true,  true);
+    assertOutput(factory.create(), sampleFile, instrumentation,  true,  true,  true);
   }
 
   /**