Make ConnectJob::ReleaseSocket() return NULL on connection error.

net/socket/client_socket_pool_base.h

 // Copyright (c) 2006-2008 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_CLIENT_SOCKET_POOL_BASE_H_
 #define NET_SOCKET_CLIENT_SOCKET_POOL_BASE_H_
 
 #include <deque>
 #include <map>
 #include <string>
@@ skipping 34 matching lines @@
   ConnectJob(const std::string& group_name,
              const ClientSocketHandle* key_handle,
              Delegate* delegate);
   virtual ~ConnectJob();
 
   // Accessors
   const std::string& group_name() const { return group_name_; }
   LoadState load_state() const { return load_state_; }
   const ClientSocketHandle* key_handle() const { return key_handle_; }
 
-  // Releases |socket_| to the client.
+  // Releases |socket_| to the client.  On connection error, this should return
+  // NULL.
   ClientSocket* ReleaseSocket() { return socket_.release(); }
 
   // Begins connecting the socket.  Returns OK on success, ERR_IO_PENDING if it
   // cannot complete synchronously without blocking, or another net error code
   // on error.  In asynchronous completion, the ConnectJob will notify
   // |delegate_| via OnConnectJobComplete.  In both asynchronous and synchronous
   // completion, ReleaseSocket() can be called to acquire the connected socket
   // if it succeeded.
   virtual int Connect() = 0;
 
@@ skipping 185 matching lines @@
   const int max_sockets_per_group_;
 
   const scoped_ptr<ConnectJobFactory> connect_job_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ClientSocketPoolBase);
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_CLIENT_SOCKET_POOL_BASE_H_