diff --git a/quic/core/http/quic_spdy_stream_test.cc b/quic/core/http/quic_spdy_stream_test.cc
index 1451533..c45a899 100644
--- a/quic/core/http/quic_spdy_stream_test.cc
+++ b/quic/core/http/quic_spdy_stream_test.cc
@@ -331,7 +331,7 @@
             connection_->ReallyCloseConnection(error, error_details,
                                                connection_close_behavior);
           })));
-  EXPECT_CALL(*connection_, SendConnectionClosePacket(_, _, _));
+  EXPECT_CALL(*connection_, SendConnectionClosePacket(_, _));
   EXPECT_CALL(*session_, OnConnectionClosed(_, _, _))
       .WillOnce(
           Invoke([this](QuicErrorCode error, const std::string& error_details,
diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index c8bfd01..ac5101e 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -22,6 +22,7 @@
 #include "net/third_party/quiche/src/quic/core/quic_bandwidth.h"
 #include "net/third_party/quiche/src/quic/core/quic_config.h"
 #include "net/third_party/quiche/src/quic/core/quic_connection_id.h"
+#include "net/third_party/quiche/src/quic/core/quic_error_codes.h"
 #include "net/third_party/quiche/src/quic/core/quic_packet_generator.h"
 #include "net/third_party/quiche/src/quic/core/quic_pending_retransmission.h"
 #include "net/third_party/quiche/src/quic/core/quic_types.h"
@@ -2632,9 +2633,8 @@
   QUIC_LOG_FIRST_N(ERROR, 2) << ENDPOINT << error_details;
   switch (error_code) {
     case QUIC_EMSGSIZE:
-      CloseConnection(
-          QUIC_PACKET_WRITE_ERROR, error_details,
-          ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET_WITH_NO_ACK);
+      CloseConnection(QUIC_PACKET_WRITE_ERROR, error_details,
+                      ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
       break;
     default:
       // We can't send an error as the socket is presumably borked.
@@ -3018,13 +3018,8 @@
                   << ", with error: " << QuicErrorCodeToString(error) << " ("
                   << error << "), and details:  " << error_details;
 
-  if (connection_close_behavior ==
-      ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET) {
-    SendConnectionClosePacket(error, error_details, SEND_ACK);
-  } else if (connection_close_behavior ==
-             ConnectionCloseBehavior::
-                 SEND_CONNECTION_CLOSE_PACKET_WITH_NO_ACK) {
-    SendConnectionClosePacket(error, error_details, NO_ACK);
+  if (connection_close_behavior != ConnectionCloseBehavior::SILENT_CLOSE) {
+    SendConnectionClosePacket(error, error_details);
   }
 
   ConnectionCloseSource source = ConnectionCloseSource::FROM_SELF;
@@ -3037,14 +3032,15 @@
 }
 
 void QuicConnection::SendConnectionClosePacket(QuicErrorCode error,
-                                               const std::string& details,
-                                               AckBundling ack_mode) {
+                                               const std::string& details) {
   QUIC_DLOG(INFO) << ENDPOINT << "Sending connection close packet.";
   if (fix_termination_packets_) {
     QUIC_RELOADABLE_FLAG_COUNT(quic_fix_termination_packets);
     SetDefaultEncryptionLevel(GetConnectionCloseEncryptionLevel());
   }
   ClearQueuedPackets();
+  // If there was a packet write error, write the smallest close possible.
+  AckBundling ack_mode = (error == QUIC_PACKET_WRITE_ERROR) ? NO_ACK : SEND_ACK;
   ScopedPacketFlusher flusher(this, ack_mode);
   // When multiple packet number spaces is supported, an ACK frame will be
   // bundled when connection is not write blocked.
diff --git a/quic/core/quic_connection.h b/quic/core/quic_connection.h
index cf534ed..c563b39 100644
--- a/quic/core/quic_connection.h
+++ b/quic/core/quic_connection.h
@@ -931,13 +931,10 @@
     return active_effective_peer_migration_type_;
   }
 
-  // Sends the connection close packet to the peer. |ack_mode| determines
-  // whether ack frame will be bundled with the connection close packet.
-  // TODO(fayang): change |ack_mode| to bool |force_sending_ack| when
-  // deprecating quic_deprecate_ack_bundling_mode.
+  // Sends a connection close packet to the peer and includes an ACK if the ACK
+  // is not empty, the |error| is not PACKET_WRITE_ERROR, and it fits.
   virtual void SendConnectionClosePacket(QuicErrorCode error,
-                                         const std::string& details,
-                                         AckBundling ack_mode);
+                                         const std::string& details);
 
   // Returns true if the packet should be discarded and not sent.
   virtual bool ShouldDiscardPacket(const SerializedPacket& packet);
diff --git a/quic/core/quic_types.h b/quic/core/quic_types.h
index 9031d2a..cc4fe2a 100644
--- a/quic/core/quic_types.h
+++ b/quic/core/quic_types.h
@@ -173,8 +173,7 @@
 // Should a connection be closed silently or not.
 enum class ConnectionCloseBehavior {
   SILENT_CLOSE,
-  SEND_CONNECTION_CLOSE_PACKET,
-  SEND_CONNECTION_CLOSE_PACKET_WITH_NO_ACK
+  SEND_CONNECTION_CLOSE_PACKET
 };
 
 enum QuicFrameType : uint8_t {
diff --git a/quic/quartc/quartc_session.cc b/quic/quartc/quartc_session.cc
index 79bc9bf..4d36305 100644
--- a/quic/quartc/quartc_session.cc
+++ b/quic/quartc/quartc_session.cc
@@ -208,7 +208,7 @@
 void QuartcSession::CloseConnection(const std::string& details) {
   connection_->CloseConnection(
       QuicErrorCode::QUIC_CONNECTION_CANCELLED, details,
-      ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET_WITH_NO_ACK);
+      ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
 }
 
 void QuartcSession::SetDelegate(Delegate* session_delegate) {
diff --git a/quic/test_tools/quic_test_utils.h b/quic/test_tools/quic_test_utils.h
index 91f25d5..52ea280 100644
--- a/quic/test_tools/quic_test_utils.h
+++ b/quic/test_tools/quic_test_utils.h
@@ -477,10 +477,8 @@
                void(QuicErrorCode error,
                     const std::string& details,
                     ConnectionCloseBehavior connection_close_behavior));
-  MOCK_METHOD3(SendConnectionClosePacket,
-               void(QuicErrorCode error,
-                    const std::string& details,
-                    AckBundling ack_mode));
+  MOCK_METHOD2(SendConnectionClosePacket,
+               void(QuicErrorCode error, const std::string& details));
   MOCK_METHOD3(SendRstStream,
                void(QuicStreamId id,
                     QuicRstStreamErrorCode error,