[Chromecast] Add support for different playback rates to ALSA backend

chromecast/media/cma/backend/alsa/stream_mixer_alsa_input_impl.h

 // Copyright 2015 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.
 
 #ifndef CHROMECAST_MEDIA_CMA_BACKEND_ALSA_STREAM_MIXER_ALSA_INPUT_IMPL_H_
 #define CHROMECAST_MEDIA_CMA_BACKEND_ALSA_STREAM_MIXER_ALSA_INPUT_IMPL_H_
 
 #include <deque>
 #include <memory>
 
@@ skipping 151 matching lines @@
   int queued_frames_;
   double queued_frames_including_resampler_;
   MediaPipelineBackendAlsa::RenderingDelay mixer_rendering_delay_;
   // End of members that queue_lock_ controls access for.
 
   int current_buffer_offset_;
   int max_queued_frames_;
   int fade_frames_remaining_;
   int fade_out_frames_total_;
   int zeroed_frames_;  // current count of consecutive 0-filled frames
+  bool is_underflowing_;
 
   OnReadyToDeleteCb delete_cb_;
 
   std::unique_ptr<::media::MultiChannelResampler> resampler_;
 
   base::WeakPtr<StreamMixerAlsaInputImpl> weak_this_;
   base::WeakPtrFactory<StreamMixerAlsaInputImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(StreamMixerAlsaInputImpl);
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_BACKEND_ALSA_STREAM_MIXER_ALSA_INPUT_IMPL_H_