Implementation of 'AudioContext.getOutputTimestamp' method

media/audio/win/audio_low_latency_output_win.h

Index: media/audio/win/audio_low_latency_output_win.h
diff --git a/media/audio/win/audio_low_latency_output_win.h b/media/audio/win/audio_low_latency_output_win.h
index 97d81b93fc61493af7ac3e0227856565e675e987..c07bf5c0a242f0bc3903e90ec699fdd4b456793f 100644
--- a/media/audio/win/audio_low_latency_output_win.h
+++ b/media/audio/win/audio_low_latency_output_win.h
@@ -239,6 +239,11 @@ class MEDIA_EXPORT WASAPIAudioOutputStream :
   // This event will be signaled when rendering shall stop.
   base::win::ScopedHandle stop_render_event_;
 
+  // A ratio used to convert 100-nanosecond 'pu64QPCPosition' time units
+  // (obtained from IAudioClock::GetPosition()) to raw performance counter
+  // time units.
+  double hns_units_to_perf_count_;
+
   // Container for retrieving data from AudioSourceCallback::OnMoreData().
   std::unique_ptr<AudioBus> audio_bus_;