Replace QuicheOptional with absl::optional.

PiperOrigin-RevId: 336947387
Change-Id: I20fa90b62347b2fbb08e68db34a22cd182ef2b64
diff --git a/quic/core/quic_stream.h b/quic/core/quic_stream.h
index 89d1a85..89178c4 100644
--- a/quic/core/quic_stream.h
+++ b/quic/core/quic_stream.h
@@ -23,6 +23,7 @@
 #include <string>
 
 #include "absl/strings/string_view.h"
+#include "absl/types/optional.h"
 #include "net/third_party/quiche/src/quic/core/quic_flow_controller.h"
 #include "net/third_party/quiche/src/quic/core/quic_packets.h"
 #include "net/third_party/quiche/src/quic/core/quic_stream_send_buffer.h"
@@ -33,7 +34,6 @@
 #include "net/third_party/quiche/src/quic/platform/api/quic_export.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_mem_slice_span.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_reference_counted.h"
-#include "net/third_party/quiche/src/common/platform/api/quiche_optional.h"
 #include "net/third_party/quiche/src/spdy/core/spdy_protocol.h"
 
 namespace quic {
@@ -440,7 +440,7 @@
              StreamType type,
              uint64_t stream_bytes_read,
              bool fin_received,
-             quiche::QuicheOptional<QuicFlowController> flow_controller,
+             absl::optional<QuicFlowController> flow_controller,
              QuicFlowController* connection_flow_controller);
 
   // Calls MaybeSendBlocked on the stream's flow controller and the connection
@@ -509,7 +509,7 @@
   // True if this stream has received a RST_STREAM frame.
   bool rst_received_;
 
-  quiche::QuicheOptional<QuicFlowController> flow_controller_;
+  absl::optional<QuicFlowController> flow_controller_;
 
   // The connection level flow controller. Not owned.
   QuicFlowController* connection_flow_controller_;