Unify VideoCodecType to/from string functionality

webrtc/modules/video_coding/utility/ivf_file_writer.cc

Index: webrtc/modules/video_coding/utility/ivf_file_writer.cc
diff --git a/webrtc/modules/video_coding/utility/ivf_file_writer.cc b/webrtc/modules/video_coding/utility/ivf_file_writer.cc
index 4198dfea496ab3036d959ad6808ce73df78524b6..d01d0231e854482c851d438e23bf8b71482d93cc 100644
--- a/webrtc/modules/video_coding/utility/ivf_file_writer.cc
+++ b/webrtc/modules/video_coding/utility/ivf_file_writer.cc
@@ -122,20 +122,8 @@ bool IvfFileWriter::InitFromFirstFrame(const EncodedImage& encoded_image,
   if (!WriteHeader())
     return false;
 
-  std::string codec_name;
-  switch (codec_type_) {
-    case kVideoCodecVP8:
-      codec_name = "VP8";
-      break;
-    case kVideoCodecVP9:
-      codec_name = "VP9";
-      break;
-    case kVideoCodecH264:
-      codec_name = "H264";
-      break;
-    default:
-      codec_name = "Unknown";
-  }
+  const char* codec_name =
+      CodecTypeToPayloadName(codec_type_).value_or("Unknown");
   LOG(LS_WARNING) << "Created IVF file for codec data of type " << codec_name
                   << " at resolution " << width_ << " x " << height_
                   << ", using " << (using_capture_timestamps_ ? "1" : "90")