Clean up the pretty-printing of QUIC frames to be internally consistent.

net/quic/quic_protocol.h

Index: net/quic/quic_protocol.h
diff --git a/net/quic/quic_protocol.h b/net/quic/quic_protocol.h
index 87b2326b22e727bbc37a51e239296dec48a3b402..6cdb496aaabc058b192015b05e404715c3e72b3e 100644
--- a/net/quic/quic_protocol.h
+++ b/net/quic/quic_protocol.h
@@ -780,6 +780,9 @@ struct NET_EXPORT_PRIVATE QuicPaddingFrame {
   explicit QuicPaddingFrame(int num_padding_bytes)
       : num_padding_bytes(num_padding_bytes) {}
 
+  NET_EXPORT_PRIVATE friend std::ostream& operator<<(std::ostream& os,
+                                                     const QuicPaddingFrame& s);
+
   // -1: full padding to the end of a max-sized packet
   // otherwise: only pad up to num_padding_bytes bytes
   int num_padding_bytes;