Set audio format before adding pepper sink to audio track.

content/renderer/pepper/pepper_media_stream_audio_track_host.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/pepper/pepper_media_stream_audio_track_host.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 346 matching lines @@
 }
 
 void PepperMediaStreamAudioTrackHost::OnNewBufferEnqueued() {
   int32_t index = buffer_manager()->DequeueBuffer();
   DCHECK_GE(index, 0);
   audio_sink_.EnqueueBuffer(index);
 }
 
 void PepperMediaStreamAudioTrackHost::DidConnectPendingHostToResource() {
   if (!connected_) {
+    media::AudioParameters format =
+        MediaStreamAudioSink::GetFormatFromAudioTrack(track_);
+    // Although this should only be called on the audio capture thread, that
+    // can't happen until the sink is added to the audio track below.
+    if (format.IsValid())
+      audio_sink_.OnSetFormat(format);
+
     MediaStreamAudioSink::AddToAudioTrack(&audio_sink_, track_);
     connected_ = true;
   }
 }
 
 }  // namespace content