Returns all preferences as a dictionary. If |include_defaults| is true (1)
then preferences currently at their default value will be included. The
returned object contains a copy of the underlying preference values and
modifications to the returned object will not modify the underlying
preference values. This function must be called on the browser process UI
thread.
Returns all preferences as a dictionary. If |include_defaults| is true (1) then preferences currently at their default value will be included. The returned object contains a copy of the underlying preference values and modifications to the returned object will not modify the underlying preference values. This function must be called on the browser process UI thread.