`EditText` supports two different forms of leading:
1. Font-provided leading, specified relative to the EM square and scaled with font size
2. User-specificed leading, specified in pixels
Notably, the former appears to apply to the first line in the text and pushes it down. This showed up in the `edittext_font_size` test, and according to that test result the leading is rounded *up* to the nearest pixel, plus one.
That last bit seems possibly wrong and is subject to further change, but it matches the tests at multiple scales.