Emits the [signal@Gtk.
TextTagTable:GtkTextTag:tag-changed] signal on the `GtkTextTagTable` where the tag is included.
The signal is already emitted when setting a `GtkTextTag` property. This function is useful for a `GtkTextTag` subclass.
| this |
a `GtkTextTag` |
| size_changed |
whether the change affects the `GtkTextView` layout |