Height of a WebView

I have a StackLayout with a WebView followed by some other controls. The WebView should be as high as its contents.

Unfortunately the WebView doesn't occupy any space at all unless I set its HeightRequest.

For Android I found this SO question which uses the ViewTreeObserver. I tried that in a custom renderer and I do get a height at some point in time, but when I tried to set the Layout of the WebView, then the controls below it will not move down. It I call ForceLayout() on the StackLayout, then the method is called recursively (even though I removed the PreDraw handler already).

private void ViewTreeObserver_PreDraw(object sender, ViewTreeObserver.PreDrawEventArgs e)
{
    var height = Control.ContentHeight;
    if(height > 0 && height != Element.Height && Element.HeightRequest <= 0)
    {
        Control.ViewTreeObserver.PreDraw -= ViewTreeObserver_PreDraw;
        Element.Layout(new Rectangle(Element.X, Element.Y, Element.Width, height));
        ((StackLayout)Element.Parent).ForceLayout();
    }
}

How can I set the Height of the WebView to be as high as its content on Android and iOS?