This function should have never been made public in the first place; its
output depends on a configuration option of Clutter, and it's basically
useful only for internal debugging.
Setting the default frame rate does not do anything even remotely
useful, unless synchronization to the vertical refresh rate is also
disabled - which can only be done through environment variable or
through configuration file. Having a programmatic way to change the
default frame rate is, thus, completely pointless.
Changing the default frame rate through environment variable and
configuration file is still allowed.
