af574f2aae
For [flutter/flutter/125875](https://github.com/flutter/flutter/issues/125875) When registering customized TextInputControl, the _PlatformTextInputControl sends inputType = TextInputType.none to the engine. After receiving TextInputType.none, the engine on the Web will create a `<input>` element instead of `<textarea>`. So there is no way to input \n(multiline). This is my solution. I tested in Android Chrome, iOS Safari, and macOS Chrome. It works for me. But I'm not sure about other use cases. I pleasure, If someone gives me suggestions.