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

net/socket/client_socket_pool_base.h

Index: net/socket/client_socket_pool_base.h
diff --git a/net/socket/client_socket_pool_base.h b/net/socket/client_socket_pool_base.h
index 8c4b3e7be90d12dff862f67a00d04bdf9b8f9d93..b7df105bf7a9b5a43a1b74d2557ccd437a002f8a 100644
--- a/net/socket/client_socket_pool_base.h
+++ b/net/socket/client_socket_pool_base.h
@@ -52,7 +52,8 @@ class ConnectJob {
   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