Mixing audio with different latency requirements

media/base/audio_renderer_mixer_input.h

 // Copyright (c) 2012 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.
 //
 // THREAD SAFETY
 //
 // This class is generally not thread safe. Callers should ensure thread safety.
 // For instance, the |sink_lock_| in WebAudioSourceProvider synchronizes access
 // to this object across the main thread (for WebAudio APIs) and the
 // media thread (for HTMLMediaElement APIs).
 //
 // The one exception is protection for |volume_| via |volume_lock_|. This lock
 // prevents races between SetVolume() (called on any thread) and ProvideInput
 // (called on audio device thread). See http://crbug.com/588992.
 
 #ifndef MEDIA_BASE_AUDIO_RENDERER_MIXER_INPUT_H_
 #define MEDIA_BASE_AUDIO_RENDERER_MIXER_INPUT_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/synchronization/lock.h"
 #include "media/base/audio_converter.h"
+#include "media/base/audio_latency.h"
 #include "media/base/audio_renderer_sink.h"
 #include "url/origin.h"
 
 namespace media {
 
 class AudioRendererMixerPool;
 class AudioRendererMixer;
 
 class MEDIA_EXPORT AudioRendererMixerInput
     : NON_EXPORTED_BASE(public SwitchableAudioRendererSink),
       public AudioConverter::InputCallback {
  public:
   AudioRendererMixerInput(AudioRendererMixerPool* mixer_pool,
                           int owner_id,
                           const std::string& device_id,
-                          const url::Origin& security_origin);
+                          const url::Origin& security_origin,
+                          AudioLatency::LatencyType latency);
 
   // SwitchableAudioRendererSink implementation.
   void Start() override;
   void Stop() override;
   void Play() override;
   void Pause() override;
   bool SetVolume(double volume) override;
   OutputDeviceInfo GetOutputDeviceInfo() override;
   void Initialize(const AudioParameters& params,
                   AudioRendererSink::RenderCallback* renderer) override;
@@ skipping 24 matching lines @@
 
   // AudioConverter::InputCallback implementation.
   double ProvideInput(AudioBus* audio_bus, uint32_t frames_delayed) override;
 
   // AudioParameters received during Initialize().
   AudioParameters params_;
 
   const int owner_id_;
   std::string device_id_;  // ID of hardware device to use
   url::Origin security_origin_;
+  const AudioLatency::LatencyType latency_;
 
   // AudioRendererMixer obtained from mixer pool during Initialize(),
   // guaranteed to live (at least) until it is returned to the pool.
   AudioRendererMixer* mixer_;
 
   // Source of audio data which is provided to the mixer.
   AudioRendererSink::RenderCallback* callback_;
 
   // Error callback for handing to AudioRendererMixer.
   const base::Closure error_cb_;
 
   // Pending switch-device callback, in case SwitchOutputDevice() is invoked
   // before Start()
   OutputDeviceStatusCB pending_switch_callback_;
   std::string pending_switch_device_id_;
   url::Origin pending_switch_security_origin_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioRendererMixerInput);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_RENDERER_MIXER_INPUT_H_