Change HTTP/3 frames from Lengh-Type-Value to Type-Length-Value.

Updating to IETF draft 19.

gfe-relnote: n/a --version 99 only, not yet enabled.
PiperOrigin-RevId: 244687780
Change-Id: Id8f42caad0c1dd2978e1a0a45aa2f462dcd0bcf8
diff --git a/quic/core/http/http_decoder.h b/quic/core/http/http_decoder.h
index 8ed7973..43a6d2c 100644
--- a/quic/core/http/http_decoder.h
+++ b/quic/core/http/http_decoder.h
@@ -129,15 +129,15 @@
     STATE_ERROR
   };
 
-  // Reads the length of a frame from |reader|. Sets error_ and error_detail_
-  // if there are any errors.
-  void ReadFrameLength(QuicDataReader* reader);
-
   // Reads the type of a frame from |reader|. Sets error_ and error_detail_
   // if there are any errors.  Also calls OnDataFrameStart() or
   // OnHeadersFrameStart() for appropriate frame types.
   void ReadFrameType(QuicDataReader* reader);
 
+  // Reads the length of a frame from |reader|. Sets error_ and error_detail_
+  // if there are any errors.
+  void ReadFrameLength(QuicDataReader* reader);
+
   // Reads the payload of the current frame from |reader| and processes it,
   // possibly buffering the data or invoking the visitor.
   void ReadFramePayload(QuicDataReader* reader);