message: Remove spurious onBufferChange() declaration.
diff: @@ -100,7 +100,6 @@ private:
  virtual IoResult doReadFromSocket();
  virtual IoResult doWriteToSocket();
  - void onBufferChange(ConnectionBufferType type, uint64_t old_size, int64_t delta);
  virtual void onConnected();
  void onFileEvent(uint32_t events);
  void onRead(uint64_t read_buffer_size);
  