I took a quick look sometimes ago to the nsIClearDataService, and I noticed that it is already started to be used internally by Firefox Desktop's Sanitizer.jsm.
Sanitizer.jsm is what browsingData API is using internally to implement most of its features, and so it seems to me that a good strategy would be to double-check if Sanitizer.jsm is now able to cover more of what browsingData needs thanks to nsIClearDataServer.
By looking to Firefox Desktop browsingData API implementation, it seems that the following features are the only ones that are not using methods from Sanitizer.jsm:
At a first glance it seems that nsIClearDataService.idl should be able to cover clearCookies and clearPassword, but it doesn't seem to be possible to clear IndexedDB and localStorage separately, is that right?
As additional side notes:
we have two separate implementations of the browsingData API namespace:
Both these API modules uses Sanitizer.jsm internally for most of the feature implemented, and Sanitizer.jsm seems to also have two separate implementations:
At a first glance it looks that, while nsIClearDataService is already been using internally by the Firefox Desktop Sanitizer.jsm, it doesn't seem to be used by the Firefox for Android Sanitizer.jsm.
Do you know if there is any actual reason why nsIClearDataService is not being used in the Firefox for Android Sanitizer.jsm?