Remove unused "using" declaration in QuicConnectionTest.

net/quic/core/quic_connection_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 "net/quic/core/quic_connection.h"
 
 #include <errno.h>
 #include <memory>
 #include <ostream>
 #include <utility>
@@ skipping 26 matching lines @@
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using base::StringPiece;
 using std::map;
 using std::ostream;
 using std::string;
 using std::vector;
 using testing::AnyNumber;
 using testing::AtLeast;
-using testing::Contains;
 using testing::DoAll;
 using testing::InSequence;
 using testing::InvokeWithoutArgs;
 using testing::NiceMock;
 using testing::Ref;
 using testing::Return;
 using testing::SaveArg;
 using testing::SetArgPointee;
 using testing::StrictMock;
 using testing::_;
@@ skipping 5059 matching lines @@
                             error_details, ConnectionCloseSource::FROM_PEER));
   connection_.set_perspective(Perspective::IS_CLIENT);
   connection_.CloseConnection(QUIC_CRYPTO_HANDSHAKE_STATELESS_REJECT,
                               error_details,
                               ConnectionCloseBehavior::SILENT_CLOSE);
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace net