Frame setters don't work right on iPad modal views

I've got a view that I'm applying this style to:

``` ruby
def container(st)
st.frame = {
l: 10,
fr: 10,
h: 320,
}
st.background_color = color.green
end
end
```

When I run it in a fullscreen modal on iPhone, it works great. But when I run it as a `UIModalPresentationFormSheet` modal on iPad it doesn't calculate the parent view size correctly and things get all wonky. I tried rotating the device to get it to reapply the styles, but to no avail.


Start with the container(st) method and its st.frame assignment, then reproduce the fullscreen iPhone and UIModalPresentationFormSheet iPad cases described in the report. Done means frame setters calculate the parent view size correctly for the iPad modal instead of producing the reported layout errors.

Written by the indexing model from the issue text.