Read and interpret PRIORITY_UPDATE frame.

gfe-relnote: n/a, change to QUIC v99-only code.  Protected by existing disabled gfe2_reloadable_flag_quic_enable_version_99.
PiperOrigin-RevId: 290869051
Change-Id: Ie5c016bd4254bffad7910d248e483976a249a27d
diff --git a/quic/core/quic_session.h b/quic/core/quic_session.h
index 6aa2b0a..f473156 100644
--- a/quic/core/quic_session.h
+++ b/quic/core/quic_session.h
@@ -636,6 +636,10 @@
   // times is safe.
   void DeleteConnection();
 
+  // Call SetPriority() on stream id |id| and return true if stream is active.
+  bool MaybeSetStreamPriority(QuicStreamId stream_id,
+                              const spdy::SpdyStreamPrecedence& precedence);
+
  private:
   friend class test::QuicSessionPeer;