Make QuicSpdyStream::ParseHeaderStatusCode() inparam const.

net/quic/quic_spdy_stream.h

Index: net/quic/quic_spdy_stream.h
diff --git a/net/quic/quic_spdy_stream.h b/net/quic/quic_spdy_stream.h
index 01cb647ba8ca86eb147a9dc39d85e021bb6493fd..027fe4a5a56a47fdb848036fca1e809d37f3ebf3 100644
--- a/net/quic/quic_spdy_stream.h
+++ b/net/quic/quic_spdy_stream.h
@@ -155,7 +155,8 @@ class NET_EXPORT_PRIVATE QuicSpdyStream : public ReliableQuicStream {
 
   // Returns true if header contains a valid 3-digit status and parse the status
   // code to |status_code|.
-  bool ParseHeaderStatusCode(SpdyHeaderBlock* header, int* status_code) const;
+  bool ParseHeaderStatusCode(const SpdyHeaderBlock& header,
+                             int* status_code) const;
 
   // Returns true when all data has been read from the peer, including the fin.
   bool IsDoneReading() const;