Extend MockAsyncSocket to include observer functions

Summary: Adding `addLifecycleObserver` and `removeLifecycleObserver` to support tests.

Reviewed By: yfeldblum

Differential Revision: D27163395

fbshipit-source-id: de749b2570c71a3f98cbbc8569c2990ce2c5be0c

folly/io/async/test/MockAsyncSocket.h

@@ -67,6 +67,15 @@ class MockAsyncSocket : public AsyncSocket {
   void setPreReceivedData(std::unique_ptr<IOBuf> data) override {
     return _setPreReceivedData(data);
   }
+
+  MOCK_METHOD1(
+      addLifecycleObserver,
+      void(folly::AsyncTransport::LifecycleObserver* observer));
+  MOCK_METHOD1(
+      removeLifecycleObserver,
+      bool(folly::AsyncTransport::LifecycleObserver* observer));
+  MOCK_CONST_METHOD0(
+      getLifecycleObservers, std::vector<AsyncTransport::LifecycleObserver*>());
 };
 
 } // namespace test