Deprecate gfe2_reloadable_flag_quic_no_silent_close_for_idle_timeout.

PiperOrigin-RevId: 334579904
Change-Id: I249312f64db974e7b09c39c269dc19c62ed67191
diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index ccc2166..e179981 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -538,9 +538,7 @@
       idle_timeout_connection_close_behavior_ = ConnectionCloseBehavior::
           SILENT_CLOSE_WITH_CONNECTION_CLOSE_PACKET_SERIALIZED;
     }
-    if (GetQuicReloadableFlag(quic_no_silent_close_for_idle_timeout) &&
-        config.HasClientRequestedIndependentOption(kNSLC, perspective_)) {
-      QUIC_RELOADABLE_FLAG_COUNT(quic_no_silent_close_for_idle_timeout);
+    if (config.HasClientRequestedIndependentOption(kNSLC, perspective_)) {
       idle_timeout_connection_close_behavior_ =
           ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET;
     }
diff --git a/quic/core/quic_connection_test.cc b/quic/core/quic_connection_test.cc
index 0921d95..3acac1c 100644
--- a/quic/core/quic_connection_test.cc
+++ b/quic/core/quic_connection_test.cc
@@ -10981,13 +10981,7 @@
   EXPECT_CALL(visitor_,
               OnConnectionClosed(_, ConnectionCloseSource::FROM_SELF));
   connection_.GetTimeoutAlarm()->Fire();
-  if (GetQuicReloadableFlag(quic_no_silent_close_for_idle_timeout)) {
-    TestConnectionCloseQuicErrorCode(QUIC_NETWORK_IDLE_TIMEOUT);
-  } else {
-    // Verify no connection close packet is serialized.
-    EXPECT_EQ(nullptr,
-              QuicConnectionPeer::GetConnectionClosePacket(&connection_));
-  }
+  TestConnectionCloseQuicErrorCode(QUIC_NETWORK_IDLE_TIMEOUT);
 }
 
 TEST_P(QuicConnectionTest, DonotSendPing) {