Deprecate --gfe2_reloadable_flag_quic_clear_body_manager.

PiperOrigin-RevId: 563170029

quiche/quic/core/http/quic_spdy_stream.cc

diff --git a/quiche/quic/core/http/quic_spdy_stream.cc b/quiche/quic/core/http/quic_spdy_stream.cc
index 4cc9ce4..ae13acc 100644
--- a/quiche/quic/core/http/quic_spdy_stream.cc
+++ b/quiche/quic/core/http/quic_spdy_stream.cc
@@ -1751,10 +1751,7 @@
 
   // QuicStream::CloseReadSide() releases buffered read data from
   // QuicStreamSequencer, invalidating every reference held by `body_manager_`.
-  if (GetQuicReloadableFlag(quic_clear_body_manager)) {
-    QUIC_RELOADABLE_FLAG_COUNT(quic_clear_body_manager);
-    body_manager_.Clear();
-  }
+  body_manager_.Clear();
 }
 
 #undef ENDPOINT  // undef for jumbo builds

quiche/quic/core/http/quic_spdy_stream_test.cc

diff --git a/quiche/quic/core/http/quic_spdy_stream_test.cc b/quiche/quic/core/http/quic_spdy_stream_test.cc
index 5dd7e89..f60bfba 100644
--- a/quiche/quic/core/http/quic_spdy_stream_test.cc
+++ b/quiche/quic/core/http/quic_spdy_stream_test.cc
@@ -3393,8 +3393,6 @@
     return;
   }
 
-  SetQuicReloadableFlag(quic_clear_body_manager, true);
-
   Initialize(!kShouldProcessData);
 
   ProcessHeaders(false, headers_);

quiche/quic/core/quic_flags_list.h

diff --git a/quiche/quic/core/quic_flags_list.h b/quiche/quic/core/quic_flags_list.h
index 689bbe9..cd770f8 100644
--- a/quiche/quic/core/quic_flags_list.h
+++ b/quiche/quic/core/quic_flags_list.h
@@ -41,8 +41,6 @@
 QUIC_FLAG(quic_reloadable_flag_quic_no_path_degrading_before_handshake_confirmed, true)
 // If true, check connected at the beginning of TlsHandshaker::SetReadSecret.
 QUIC_FLAG(quic_reloadable_flag_quic_check_connected_before_set_read_secret, true)
-// If true, clear QuicSpdyStreamBodyManager in QuicSpdyStream::CloseReadSide().
-QUIC_FLAG(quic_reloadable_flag_quic_clear_body_manager, true)
 // If true, consider write blocked when destination CID is required but missing on the default path.
 QUIC_FLAG(quic_reloadable_flag_quic_write_is_blocked_when_cid_is_missing, true)
 // If true, default-enable 5RTO blachole detection.