In \include\javascript\tiny_mce\themes\advanced\editor_template_src.js
I made some changes to the init function to add Calibri:
t.settings = s = extend({
[...]
theme_advanced_fonts : "Calibri=calibri,helvetica,sans-serif; [...] "
[...]
}, s);
[... and later on ...]
ed.contentCSS.push("http://fonts.googleapis.com/css?family=Calibri:300,400,700");
Obviously, that's not enough.
What's missing ? Or is my whole approach wrong?
Is there any way to do this just by changing \custom\include\tinyMCEDefaultConfig.php?