Reland: MediaCaptureFromElement: add support for audio captureStream().

media/blink/webaudiosourceprovider_impl.h

 // Copyright 2013 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 MEDIA_BLINK_WEBAUDIOSOURCEPROVIDER_IMPL_H_
 #define MEDIA_BLINK_WEBAUDIOSOURCEPROVIDER_IMPL_H_
 
 #include <stddef.h>
 
 #include <string>
@@ skipping 54 matching lines @@
   void Initialize(const AudioParameters& params,
                   RenderCallback* renderer) override;
   void SwitchOutputDevice(const std::string& device_id,
                           const url::Origin& security_origin,
                           const OutputDeviceStatusCB& callback) override;
 
   // These methods allow a client to get a copy of the rendered audio.
   void SetCopyAudioCallback(const CopyAudioCB& callback);
   void ClearCopyAudioCallback();
 
+  int RenderForTesting(AudioBus* audio_bus);
+
  private:
   friend class WebAudioSourceProviderImplTest;
   ~WebAudioSourceProviderImpl() override;
 
   // Calls setFormat() on |client_| from the Blink renderer thread.
   void OnSetFormat();
 
-  int RenderForTesting(AudioBus* audio_bus);
-
   // Used to keep the volume across reconfigurations.
   double volume_;
 
   // Tracks the current playback state.
   enum PlaybackState { kStopped, kStarted, kPlaying };
   PlaybackState state_;
 
   // Closure that calls OnSetFormat() on |client_| on the renderer thread.
   base::Closure set_format_cb_;
   // When set via setClient() it overrides |sink_| for consuming audio.
   blink::WebAudioSourceProviderClient* client_;
 
   // Where audio ends up unless overridden by |client_|.
   base::Lock sink_lock_;
   const scoped_refptr<SwitchableAudioRendererSink> sink_;
   std::unique_ptr<AudioBus> bus_wrapper_;
 
   // An inner class acting as a T filter where actual data can be tapped.
   class TeeFilter;
-  std::unique_ptr<TeeFilter> tee_filter_;
+  const std::unique_ptr<TeeFilter> tee_filter_;
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<WebAudioSourceProviderImpl> weak_factory_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(WebAudioSourceProviderImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BLINK_WEBAUDIOSOURCEPROVIDER_IMPL_H_