It doesn't need to store so much crap as attributes, and the data flow
of the init can be made more explicit.
- have setup functions return stuff, which can be set on `self` by the
`__init__`, making the dataflow more explicit
- maintain a high-level `Popen` object instead of moving a `pid` around
- pass items like browser size as parameters instead of attributes
- remove redundant attributes like `screencasts_frame_dir` (/ convert
to properties)
Part-of: odoo/odoo#111422
Xavier Morel
e6fd0ad5ee