Remove unused TestAsyncUDPSocket

Reviewed By: Orvid

Differential Revision: D16640245

fbshipit-source-id: 3a184e4d877ea27a9400de5993b494095f6bd5e5

folly/io/async/test/AsyncUDPSocketTest.cpp

@@ -421,15 +421,6 @@ TEST_F(AsyncSocketIntegrationTest, PingPongPauseResumeListening) {
   ASSERT_GT(pingClient->pongRecvd(), 0);
 }
 
-class TestAsyncUDPSocket : public AsyncUDPSocket {
- public:
-  explicit TestAsyncUDPSocket(EventBase* evb) : AsyncUDPSocket(evb) {}
-
-  MOCK_METHOD3(
-      sendmsg,
-      ssize_t(folly::NetworkSocket, const struct msghdr*, int));
-};
-
 class MockErrMessageCallback : public AsyncUDPSocket::ErrMessageCallback {
  public:
   ~MockErrMessageCallback() override = default;