Generalize manifest parser parameters in DASH and SmoothStreaming MediaSources

This allows custom parsers to be used.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=152005477

library/core/src/main/java/com/google/android/exoplayer2/upstream/ParsingLoadable.java

@@ -59,7 +59,7 @@ public final class ParsingLoadable<T> implements Loadable {
   public final int type;
 
   private final DataSource dataSource;
-  private final Parser<T> parser;
+  private final Parser<? extends T> parser;
 
   private volatile T result;
   private volatile boolean isCanceled;
@@ -71,7 +71,7 @@ public final class ParsingLoadable<T> implements Loadable {
    * @param type See {@link #type}.
    * @param parser Parses the object from the response.
    */
-  public ParsingLoadable(DataSource dataSource, Uri uri, int type, Parser<T> parser) {
+  public ParsingLoadable(DataSource dataSource, Uri uri, int type, Parser<? extends T> parser) {
     this.dataSource = dataSource;
     this.dataSpec = new DataSpec(uri, DataSpec.FLAG_ALLOW_GZIP);
     this.type = type;

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java

@@ -88,7 +88,7 @@ public final class DashMediaSource implements MediaSource {
   private final int minLoadableRetryCount;
   private final long livePresentationDelayMs;
   private final EventDispatcher eventDispatcher;
-  private final DashManifestParser manifestParser;
+  private final ParsingLoadable.Parser<? extends DashManifest> manifestParser;
   private final ManifestCallback manifestCallback;
   private final Object manifestUriLock;
   private final SparseArray<DashMediaPeriod> periodsById;
@@ -200,15 +200,17 @@ public final class DashMediaSource implements MediaSource {
    * @param eventListener A listener of events. May be null if delivery of events is not required.
    */
   public DashMediaSource(Uri manifestUri, DataSource.Factory manifestDataSourceFactory,
-      DashManifestParser manifestParser, DashChunkSource.Factory chunkSourceFactory,
+      ParsingLoadable.Parser<? extends DashManifest> manifestParser,
-      int minLoadableRetryCount, long livePresentationDelayMs, Handler eventHandler,
+      DashChunkSource.Factory chunkSourceFactory, int minLoadableRetryCount,
+      long livePresentationDelayMs, Handler eventHandler,
       AdaptiveMediaSourceEventListener eventListener) {
     this(null, manifestUri, manifestDataSourceFactory, manifestParser, chunkSourceFactory,
         minLoadableRetryCount, livePresentationDelayMs, eventHandler, eventListener);
   }
 
   private DashMediaSource(DashManifest manifest, Uri manifestUri,
-      DataSource.Factory manifestDataSourceFactory, DashManifestParser manifestParser,
+      DataSource.Factory manifestDataSourceFactory,
+      ParsingLoadable.Parser<? extends DashManifest> manifestParser,
       DashChunkSource.Factory chunkSourceFactory, int minLoadableRetryCount,
       long livePresentationDelayMs, Handler eventHandler,
       AdaptiveMediaSourceEventListener eventListener) {

library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/SsMediaSource.java

@@ -71,7 +71,7 @@ public final class SsMediaSource implements MediaSource,
   private final int minLoadableRetryCount;
   private final long livePresentationDelayMs;
   private final EventDispatcher eventDispatcher;
-  private final SsManifestParser manifestParser;
+  private final ParsingLoadable.Parser<? extends SsManifest> manifestParser;
   private final ArrayList<SsMediaPeriod> mediaPeriods;
 
   private Listener sourceListener;
@@ -171,15 +171,17 @@ public final class SsMediaSource implements MediaSource,
    * @param eventListener A listener of events. May be null if delivery of events is not required.
    */
   public SsMediaSource(Uri manifestUri, DataSource.Factory manifestDataSourceFactory,
-      SsManifestParser manifestParser, SsChunkSource.Factory chunkSourceFactory,
+      ParsingLoadable.Parser<? extends SsManifest> manifestParser,
-      int minLoadableRetryCount, long livePresentationDelayMs, Handler eventHandler,
+      SsChunkSource.Factory chunkSourceFactory, int minLoadableRetryCount,
+      long livePresentationDelayMs, Handler eventHandler,
       AdaptiveMediaSourceEventListener eventListener) {
     this(null, manifestUri, manifestDataSourceFactory, manifestParser, chunkSourceFactory,
         minLoadableRetryCount, livePresentationDelayMs, eventHandler, eventListener);
   }
 
   private SsMediaSource(SsManifest manifest, Uri manifestUri,
-      DataSource.Factory manifestDataSourceFactory, SsManifestParser manifestParser,
+      DataSource.Factory manifestDataSourceFactory,
+      ParsingLoadable.Parser<? extends SsManifest> manifestParser,
       SsChunkSource.Factory chunkSourceFactory, int minLoadableRetryCount,
       long livePresentationDelayMs, Handler eventHandler,
       AdaptiveMediaSourceEventListener eventListener) {