Implementation of 'AudioContext.getOutputTimestamp' method

third_party/WebKit/public/platform/WebAudioDevice.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 16 matching lines @@
  */
 
 #ifndef WebAudioDevice_h
 #define WebAudioDevice_h
 
 #include "WebCommon.h"
 #include "WebVector.h"
 
 namespace blink {
 
+// Representation of device audio stream position.
+
+struct BLINK_PLATFORM_EXPORT WebAudioTimestamp {
+    WebAudioTimestamp() = default;
+    WebAudioTimestamp(size_t frames, double seconds)
+        : frames(frames), seconds(seconds) {}
+    size_t frames;
+    double seconds;
+};
+
 // Abstract interface to the Chromium audio system.
 
 class WebAudioDevice {
 public:
     class BLINK_PLATFORM_EXPORT RenderCallback {
     public:
         virtual void render(const WebVector<float*>& sourceData, const WebVector<float*>& destinationData, size_t numberOfFrames);
+        // An alternate version which provides also a current audio timestamp for the device, default implementation just invokes the above method.
+        virtual void render(const WebVector<float*>& sourceData, const WebVector<float*>& destinationData, size_t numberOfFrames, const WebAudioTimestamp&);
 
     protected:
         virtual ~RenderCallback();
     };
 
     virtual ~WebAudioDevice() { }
 
     virtual void start() = 0;
     virtual void stop() = 0;
     virtual double sampleRate() = 0;
 };
 
 } // namespace blink
 
 #endif // WebAudioDevice_h