Refactoring: Hide VideoCodec.codecSpecific as "private"

webrtc/modules/video_coding/video_sender.cc

Index: webrtc/modules/video_coding/video_sender.cc
diff --git a/webrtc/modules/video_coding/video_sender.cc b/webrtc/modules/video_coding/video_sender.cc
index 0f2da583a0f63e4814fe43234fa14e6f6fdfd598..b7664a719b3a7d155d23666df94663928087bc8c 100644
--- a/webrtc/modules/video_coding/video_sender.cc
+++ b/webrtc/modules/video_coding/video_sender.cc
@@ -103,9 +103,9 @@ int32_t VideoSender::RegisterSendCodec(const VideoCodec* sendCodec,
 
   int numLayers;
   if (sendCodec->codecType == kVideoCodecVP8) {
-    numLayers = sendCodec->codecSpecific.VP8.numberOfTemporalLayers;
+    numLayers = sendCodec->VP8().numberOfTemporalLayers;
   } else if (sendCodec->codecType == kVideoCodecVP9) {
-    numLayers = sendCodec->codecSpecific.VP9.numberOfTemporalLayers;
+    numLayers = sendCodec->VP9().numberOfTemporalLayers;
   } else {
     numLayers = 1;
   }