Implementation of 'AudioContext.getOutputTimestamp' method

third_party/WebKit/Source/platform/audio/AudioIOCallback.h

 /*
  * Copyright (C) 2012 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 11 matching lines @@
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef AudioIOCallback_h
 #define AudioIOCallback_h
 
+#include "base/time/time.h"
+
 namespace blink {
 
 class AudioBus;
 
+struct AudioIOPosition {
+  // Audio stream position in seconds.
+  double position;
+  // System timestamp in seconds corresponding to the contained |position|
+  // value.
+  double timestamp;
+};
+
 // Abstract base-class for isochronous audio I/O client.
 class AudioIOCallback {
  public:
   // render() is called periodically to get the next render quantum of audio
   // into destinationBus.  Optional audio input is given in sourceBus (if it's
   // not 0).
   virtual void render(AudioBus* sourceBus,
                       AudioBus* destinationBus,
-                      size_t framesToProcess) = 0;
+                      size_t framesToProcess,
+                      const AudioIOPosition& outputPosition) = 0;
 
   virtual ~AudioIOCallback() {}
 };
 
 }  // namespace blink
 
 #endif  // AudioIOCallback_h