[Chromecast] Make ALSA rendering delay either accurate or kNoTimestamp

chromecast/media/cma/backend/alsa/alsa_wrapper.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_ALSA_WRAPPER_H_
 #define CHROMECAST_MEDIA_CMA_BACKEND_ALSA_ALSA_WRAPPER_H_
 
 #include "base/macros.h"
 #include "media/audio/alsa/alsa_wrapper.h"
 
 namespace chromecast {
 namespace media {
 
 extern const int kAlsaTstampTypeMonotonicRaw;
 
 // Extends the Chromium AlsaWrapper, adding additional functions that we use.
 class AlsaWrapper : public ::media::AlsaWrapper {
  public:
   AlsaWrapper();
   ~AlsaWrapper() override;
 
   virtual int PcmPause(snd_pcm_t* handle, int enable);
 
   virtual int PcmStatusMalloc(snd_pcm_status_t** ptr);
   virtual void PcmStatusFree(snd_pcm_status_t* obj);
   virtual int PcmStatus(snd_pcm_t* handle, snd_pcm_status_t* status);
   virtual snd_pcm_sframes_t PcmStatusGetDelay(const snd_pcm_status_t* obj);
   virtual void PcmStatusGetHtstamp(const snd_pcm_status_t* obj,
                                    snd_htimestamp_t* ptr);
+  virtual snd_pcm_state_t PcmStatusGetState(const snd_pcm_status_t* obj);
   virtual ssize_t PcmFormatSize(snd_pcm_format_t format, size_t samples);
   virtual int PcmHwParamsMalloc(snd_pcm_hw_params_t** ptr);
   virtual void PcmHwParamsFree(snd_pcm_hw_params_t* obj);
   virtual int PcmHwParamsCurrent(snd_pcm_t* handle,
                                  snd_pcm_hw_params_t* params);
   virtual int PcmHwParamsCanPause(const snd_pcm_hw_params_t* params);
   virtual int PcmHwParamsAny(snd_pcm_t* handle, snd_pcm_hw_params_t* params);
   virtual int PcmHwParamsSetRateResample(snd_pcm_t* handle,
                                          snd_pcm_hw_params_t* params,
                                          bool val);
@@ skipping 45 matching lines @@
   virtual int PcmSwParams(snd_pcm_t* handle, snd_pcm_sw_params_t* obj);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AlsaWrapper);
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_BACKEND_ALSA_ALSA_WRAPPER_H_