Deprecate gfe2_reloadable_flag_quic_close_connection_in_on_can_write_with_blocked_writer.

PiperOrigin-RevId: 343930906
Change-Id: I7f0649839ac75edd198c72139f34bfd3fa71db44

quic/core/quic_connection.cc

diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index 19d6ac3..8203bce 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -2419,20 +2419,13 @@
   if (!connected_) {
     return;
   }
-  if (GetQuicReloadableFlag(
-          quic_close_connection_in_on_can_write_with_blocked_writer)) {
-    QUIC_RELOADABLE_FLAG_COUNT(
-        quic_close_connection_in_on_can_write_with_blocked_writer);
-    if (writer_->IsWriteBlocked()) {
-      const std::string error_details =
-          "Writer is blocked while calling OnCanWrite.";
-      QUIC_BUG << ENDPOINT << error_details;
-      CloseConnection(QUIC_INTERNAL_ERROR, error_details,
-                      ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
-      return;
-    }
-  } else {
-    DCHECK(!writer_->IsWriteBlocked());
+  if (writer_->IsWriteBlocked()) {
+    const std::string error_details =
+        "Writer is blocked while calling OnCanWrite.";
+    QUIC_BUG << ENDPOINT << error_details;
+    CloseConnection(QUIC_INTERNAL_ERROR, error_details,
+                    ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
+    return;
   }
 
   // Add a flusher to ensure the connection is marked app-limited.

quic/core/quic_flags_list.h

diff --git a/quic/core/quic_flags_list.h b/quic/core/quic_flags_list.h
index 55036ee..ae001f7 100644
--- a/quic/core/quic_flags_list.h
+++ b/quic/core/quic_flags_list.h
@@ -17,7 +17,6 @@
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_bbr2_support_max_bootstrap_cwnd, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_bbr2_use_bytes_delivered, false)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_can_send_ack_frequency, true)
-QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_close_connection_in_on_can_write_with_blocked_writer, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_connection_set_initial_self_address, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_conservative_bursts, false)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_conservative_cwnd_and_pacing_gains, false)