Update from https://crrev.com/307330

net/tools/quic/end_to_end_test.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 #include <string>
 #include <sys/epoll.h>
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 1329 matching lines @@
   // Now verify that the server is not waiting for a final FIN or RST.
   server_thread_->Pause();
   QuicDispatcher* dispatcher =
       QuicServerPeer::GetDispatcher(server_thread_->server());
   QuicSession* session = dispatcher->session_map().begin()->second;
   EXPECT_EQ(0u, QuicSessionPeer::GetLocallyClosedStreamsHighestOffset(
       session).size());
   server_thread_->Resume();
 }
 
+TEST_P(EndToEndTest, EnablePacingViaFlag) {
+  // When pacing is enabled via command-line flag, it will always be enabled,
+  // regardless of the config. or the specific congestion-control algorithm.
+  ValueRestore<bool> old_flag(&FLAGS_quic_enable_pacing, true);
+  ASSERT_TRUE(Initialize());
+
+  client_->client()->WaitForCryptoHandshakeConfirmed();
+  server_thread_->WaitForCryptoHandshakeConfirmed();
+
+  // Pause the server so we can access the server's internals without races.
+  server_thread_->Pause();
+  QuicDispatcher* dispatcher =
+      QuicServerPeer::GetDispatcher(server_thread_->server());
+  ASSERT_EQ(1u, dispatcher->session_map().size());
+  const QuicSentPacketManager& client_sent_packet_manager =
+      client_->client()->session()->connection()->sent_packet_manager();
+  const QuicSentPacketManager& server_sent_packet_manager =
+      *GetSentPacketManagerFromFirstServerSession();
+  EXPECT_TRUE(server_sent_packet_manager.using_pacing());
+  EXPECT_TRUE(client_sent_packet_manager.using_pacing());
+}
+
 }  // namespace
 }  // namespace test
 }  // namespace tools
 }  // namespace net