This patch makes Firefox to spoof keyboardEvent.code, keyboardEvent.keycode and
modifier states, for 'Shift', 'Alt', 'Control' and 'AltGraph', when 'privacy.resistFingerprinting'
is true. Firefox will spoof keyboard events as a certain keyboard layout according
to the content language of the document, for example, we use US English keyboard for
English content. Right now, it only supports English contents, we will add more
support for more languages later. The spoofing only affects content, chrome
can still see real keyboard events.
MozReview-Commit-ID: 40JPvwLmMMB
https://github.com/w3c/uievents/issues/112
This is supported by all other UAs. In the past we had compatibility
problems when trying to add support, but it seems these might be fixed
if we make all arguments optional beyond the first.
The interface chosen for the method is from the spec, which has been
updated to match Chrome. This is also very similar to WebKit, but the
final four arguments are different from IE.
MozReview-Commit-ID: 36AeX1JwJTt
