Remove ack bundling mode.

gfe-relnote: Deprecate gfe2_reloadable_flag_quic_deprecate_ack_bundling_mode.
PiperOrigin-RevId: 253856112
Change-Id: Iaa62b97be5904743c56c5b48b230446a9c4bd870
diff --git a/quic/core/http/end_to_end_test.cc b/quic/core/http/end_to_end_test.cc
index fa60c96..a64b289 100644
--- a/quic/core/http/end_to_end_test.cc
+++ b/quic/core/http/end_to_end_test.cc
@@ -3612,8 +3612,7 @@
       QuicConnectionPeer::GetHelper(client_connection)->GetRandomGenerator();
   QuicMemSliceStorage storage(nullptr, 0, nullptr, 0);
   {
-    QuicConnection::ScopedPacketFlusher flusher(
-        client_session->connection(), QuicConnection::SEND_ACK_IF_PENDING);
+    QuicConnection::ScopedPacketFlusher flusher(client_session->connection());
     // Verify the largest message gets successfully sent.
     EXPECT_EQ(
         MessageResult(MESSAGE_STATUS_SUCCESS, 1),