UMA stats for browser/renderer audio rendering buffer size mismatch.

content/renderer/media/webrtc_audio_renderer.cc

Index: content/renderer/media/webrtc_audio_renderer.cc
diff --git a/content/renderer/media/webrtc_audio_renderer.cc b/content/renderer/media/webrtc_audio_renderer.cc
index e3ce2b0f6775112015b1586bed60f1a90d0f97d2..98e51b71ebdaaabe70c746efeef3cd8e295a5370 100644
--- a/content/renderer/media/webrtc_audio_renderer.cc
+++ b/content/renderer/media/webrtc_audio_renderer.cc
@@ -650,7 +650,8 @@ void WebRtcAudioRenderer::PrepareSink() {
     }
     sink_params_ = new_sink_params;
   }
-
+  new_sink_params.set_latency_tag(AudioDeviceFactory::GetSourceLatencyType(
+      AudioDeviceFactory::AudioDeviceFactory::kSourceWebRtc));
   sink_->Initialize(new_sink_params, this);
 }