Revert of Add Stop() to AudioDecoder.

media/filters/audio_decoder_selector.cc

Index: media/filters/audio_decoder_selector.cc
diff --git a/media/filters/audio_decoder_selector.cc b/media/filters/audio_decoder_selector.cc
index f0de25d220a61829b3c44324fdec42f8a01186cf..4f7889b2619f3793a85765522d7ec2a1d6f5d34a 100644
--- a/media/filters/audio_decoder_selector.cc
+++ b/media/filters/audio_decoder_selector.cc
@@ -90,10 +90,10 @@
   weak_ptr_factory_.InvalidateWeakPtrs();
 
   if (audio_decoder_) {
-    // |decrypted_stream_| is either NULL or already initialized. We don't
-    // need to Reset() |decrypted_stream_| in either case.
-    audio_decoder_->Stop(base::Bind(&AudioDecoderSelector::ReturnNullDecoder,
-                                    weak_ptr_factory_.GetWeakPtr()));
+    // AudioDecoder doesn't provide a Stop() method. Also, |decrypted_stream_|
+    // is either NULL or already initialized. We don't need to Reset()
+    // |decrypted_stream_| in either case.
+    ReturnNullDecoder();
     return;
   }