First step to remove SingleRequestHostResolver.

net/socket/websocket_transport_client_socket_pool.h

 // Copyright 2014 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.
 
 #ifndef NET_SOCKET_WEBSOCKET_TRANSPORT_CLIENT_SOCKET_POOL_H_
 #define NET_SOCKET_WEBSOCKET_TRANSPORT_CLIENT_SOCKET_POOL_H_
 
 #include <list>
 #include <map>
 #include <memory>
@@ skipping 85 matching lines @@
 
   // Called from |fallback_timer_|.
   void StartIPv4JobAsync();
 
   // Begins the host resolution and the TCP connect.  Returns OK on success
   // and ERR_IO_PENDING if it cannot immediately service the request.
   // Otherwise, it returns a net error code.
   int ConnectInternal() override;
 
   scoped_refptr<TransportSocketParams> params_;
-  SingleRequestHostResolver resolver_;
+  HostResolver* resolver_;
+  std::unique_ptr<HostResolver::Request> request_;
   ClientSocketFactory* const client_socket_factory_;
 
   State next_state_;
 
   AddressList addresses_;
   // The addresses are divided into IPv4 and IPv6, which are performed partially
   // in parallel. If the list of IPv6 addresses is non-empty, then the IPv6 jobs
   // go first, followed after |kIPv6FallbackTimerInMs| by the IPv4
   // addresses. First sub-job to establish a connection wins.
   std::unique_ptr<WebSocketTransportConnectSubJob> ipv4_job_;
@@ skipping 134 matching lines @@
   bool flushing_;
 
   base::WeakPtrFactory<WebSocketTransportClientSocketPool> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WebSocketTransportClientSocketPool);
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_WEBSOCKET_TRANSPORT_CLIENT_SOCKET_POOL_H_