Chrome spellchecking does not work in CKEditor

Chrome natively spell checks text as user types in textarea boxes. But in CKEditor, it doesn't seem to be working (probably because CKEditor runs as an iframe).

CKEditor has an inbuilt spell checking extension but it makes a service call to another service to do so. This has security concerns if the data being typed is confidential.

So, can this feature be natively supported in CKEditor so as to not require an external service call?