Distinguish exceptions caught at top level.

library/src/main/java/com/google/android/exoplayer/ExoPlaybackException.java

@@ -20,18 +20,32 @@ package com.google.android.exoplayer;
  * <p>
  * Where possible, the cause returned by {@link #getCause()} will indicate the reason for failure.
  */
-public class ExoPlaybackException extends Exception {
+public final class ExoPlaybackException extends Exception {
+
+  /**
+   * True if the cause (i.e. the {@link Throwable} returned by {@link #getCause()}) was only caught
+   * by a fail-safe at the top level of the player. False otherwise.
+   */
+  public final boolean caughtAtTopLevel;
 
   public ExoPlaybackException(String message) {
     super(message);
+    caughtAtTopLevel = false;
   }
 
   public ExoPlaybackException(Throwable cause) {
     super(cause);
+    caughtAtTopLevel = false;
   }
 
   public ExoPlaybackException(String message, Throwable cause) {
     super(message, cause);
+    caughtAtTopLevel = false;
+  }
+
+  /* package */ ExoPlaybackException(Throwable cause, boolean caughtAtTopLevel) {
+    super(cause);
+    this.caughtAtTopLevel = caughtAtTopLevel;
   }
 
 }

library/src/main/java/com/google/android/exoplayer/ExoPlayerImplInternal.java

@@ -233,7 +233,7 @@ import java.util.List;
       return true;
     } catch (RuntimeException e) {
       Log.e(TAG, "Internal runtime error.", e);
-      eventHandler.obtainMessage(MSG_ERROR, new ExoPlaybackException(e)).sendToTarget();
+      eventHandler.obtainMessage(MSG_ERROR, new ExoPlaybackException(e, true)).sendToTarget();
       stopInternal();
       return true;
     }