Remove QuicChromiumClientStream::Delegate in favor of async methods.

net/quic/chromium/quic_network_transaction_unittest.cc

Index: net/quic/chromium/quic_network_transaction_unittest.cc
diff --git a/net/quic/chromium/quic_network_transaction_unittest.cc b/net/quic/chromium/quic_network_transaction_unittest.cc
index 1762682fa086d5013c3b15d4c7c7ac23c9d8146a..0d56c1d49b71e99e0098ff87acb016a814ec02fe 100644
--- a/net/quic/chromium/quic_network_transaction_unittest.cc
+++ b/net/quic/chromium/quic_network_transaction_unittest.cc
@@ -1206,8 +1206,6 @@ TEST_P(QuicNetworkTransactionTest, RetryMisdirectedRequest) {
   mock_quic_data.AddRead(ConstructServerResponseHeadersPacket(
       1, GetNthClientInitiatedStreamId(0), false, true,
       GetResponseHeaders("421"), nullptr));
-  mock_quic_data.AddWrite(ConstructClientAckAndRstPacket(
-      3, GetNthClientInitiatedStreamId(0), QUIC_STREAM_CANCELLED, 1, 1, 1));
   mock_quic_data.AddRead(ASYNC, OK);
   mock_quic_data.AddSocketDataToFactory(&socket_factory_);