Clear fatal errors in Loader#startLoading

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=189323050

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

@@ -159,22 +159,23 @@ public final class Loader implements LoaderErrorThrower {
 
   /**
    * Starts loading a {@link Loadable}.
-   * <p>
-   * The calling thread must be a {@link Looper} thread, which is the thread on which the
-   * {@link Callback} will be called.
+   *
+   * <p>The calling thread must be a {@link Looper} thread, which is the thread on which the {@link
+   * Callback} will be called.
    *
    * @param <T> The type of the loadable.
    * @param loadable The {@link Loadable} to load.
    * @param callback A callback to be called when the load ends.
-   * @param defaultMinRetryCount The minimum number of times the load must be retried before
-   *     {@link #maybeThrowError()} will propagate an error.
+   * @param defaultMinRetryCount The minimum number of times the load must be retried before {@link
+   *     #maybeThrowError()} will propagate an error.
    * @throws IllegalStateException If the calling thread does not have an associated {@link Looper}.
    * @return {@link SystemClock#elapsedRealtime} when the load started.
    */
-  public <T extends Loadable> long startLoading(T loadable, Callback<T> callback,
-      int defaultMinRetryCount) {
+  public <T extends Loadable> long startLoading(
+      T loadable, Callback<T> callback, int defaultMinRetryCount) {
     Looper looper = Looper.myLooper();
     Assertions.checkState(looper != null);
+    fatalError = null;
     long startTimeMs = SystemClock.elapsedRealtime();
     new LoadTask<>(looper, loadable, callback, defaultMinRetryCount, startTimeMs).start(0);
     return startTimeMs;