Add AsyncSocket::UniquePtr ctor coro::Socket

Summary: This diff is part of a series cleaning up coro::Socket

Reviewed By: yairgott

Differential Revision: D26837067

fbshipit-source-id: e7ef587a6f859a167404b3eb2c8399544aa1d092

folly/io/coro/Socket.h

@@ -74,6 +74,9 @@ class Socket : public Transport {
   explicit Socket(std::shared_ptr<AsyncSocket> socket)
       : socket_(std::move(socket)) {}
 
+  explicit Socket(AsyncSocket::UniquePtr socket)
+      : socket_(socket.release(), AsyncSocket::Destructor()) {}
+
   Socket(Socket&&) = default;
   Socket& operator=(Socket&&) = default;