message: Don't mock setKnob.
  Summary: As in title. Mocking a unique ptr function doesn't really work.
diff: @@ -83,9 +83,17 @@ class MockQuicSocket : public QuicSocket {
  setStreamFlowControlWindow,
  folly::Expected<folly::Unit, LocalErrorCode>(StreamId, uint64_t));
  MOCK_METHOD1(setTransportSettings, void(TransportSettings));
  + folly::Expected<folly::Unit, LocalErrorCode>
  + setKnob(uint64_t knobSpace, uint64_t knobId, Buf knobBlob) override {
  + SharedBuf sharedBlob(knobBlob.release());
  + return setKnob(knobSpace, knobId, sharedBlob);
  + }
  MOCK_METHOD3(
  setKnob,
  - folly::Expected<folly::Unit, LocalErrorCode>(uint64_t, uint64_t, Buf));
  + folly::Expected<folly::Unit, LocalErrorCode>(
  + uint64_t,
  + uint64_t,
  + SharedBuf));
  MOCK_CONST_METHOD0(isPartiallyReliableTransport, bool());
  MOCK_METHOD3(
  setReadCallback,
  