Use a QuicSession member to latch
gfe2_reloadable_flag_quic_eliminate_static_stream_map_2.

This prevents unexpected behavior from runtime flag flipping.

gfe-relnote: gfe2_reloadable_flag_quic_eliminate_static_stream_map_2 replaces
gfe2_reloadable_flag_quic_eliminate_static_stream_map for rollout purposes.
PiperOrigin-RevId: 246926123
Change-Id: I11103af393e7fa93ea5b2d3cd90f9fe423fbed96
diff --git a/quic/core/http/quic_spdy_session.h b/quic/core/http/quic_spdy_session.h
index 9248fa5..23e57c3 100644
--- a/quic/core/http/quic_spdy_session.h
+++ b/quic/core/http/quic_spdy_session.h
@@ -140,15 +140,13 @@
   QpackEncoder* qpack_encoder();
   QpackDecoder* qpack_decoder();
   QuicHeadersStream* headers_stream() {
-    return GetQuicReloadableFlag(quic_eliminate_static_stream_map)
-               ? unowned_headers_stream_
-               : headers_stream_.get();
+    return eliminate_static_stream_map() ? unowned_headers_stream_
+                                         : headers_stream_.get();
   }
 
   const QuicHeadersStream* headers_stream() const {
-    return GetQuicReloadableFlag(quic_eliminate_static_stream_map)
-               ? unowned_headers_stream_
-               : headers_stream_.get();
+    return eliminate_static_stream_map() ? unowned_headers_stream_
+                                         : headers_stream_.get();
   }
 
   bool server_push_enabled() const { return server_push_enabled_; }