Remove some unnecessary using directives from tests.

net/tools/quic/quic_client_session_test.cc

Index: net/tools/quic/quic_client_session_test.cc
diff --git a/net/tools/quic/quic_client_session_test.cc b/net/tools/quic/quic_client_session_test.cc
index b086a218b23dcbbd5443b53dcadf4981f849581a..4e9b68e6ad407bf6748df00b947e8eb68bb790a9 100644
--- a/net/tools/quic/quic_client_session_test.cc
+++ b/net/tools/quic/quic_client_session_test.cc
@@ -24,22 +24,6 @@
 
 using base::StringPrintf;
 using google::protobuf::implicit_cast;
-using net::test::ConstructEncryptedPacket;
-using net::test::ConstructMisFramedEncryptedPacket;
-using net::test::CryptoTestUtils;
-using net::test::DefaultQuicConfig;
-using net::test::MockQuicConnection;
-using net::test::MockQuicConnectionHelper;
-using net::test::MockQuicSpdyClientStream;
-using net::test::PacketSavingConnection;
-using net::test::QuicConnectionPeer;
-using net::test::QuicPacketCreatorPeer;
-using net::test::QuicSpdySessionPeer;
-using net::test::SupportedVersions;
-using net::test::TestPeerIPAddress;
-using net::test::kClientDataStreamId1;
-using net::test::kServerDataStreamId1;
-using net::test::kTestPort;
 using std::string;
 using testing::AnyNumber;
 using testing::Invoke;