In legacy/trac#1517, the idea was to round most event time stamps to 100ms, but to round KeyboardEvent.timeStamp to 250 ms (see https://trac.torproject.org/projects/tor/ticket/1517#comment:25). Our current patch for legacy/trac#1517 is [here](https://gitweb.torproject.org/tor-browser.git/commit/?h=tor-browser-45.1.1esr-6.0-1&id=191e520147e00b1a103b9fd91ad37fa4b0cf9d28). However, when I test KeyboardEvents in the latest Tor Browser, I only see rounding to 100 ms. With the debugger I observed that calling myKeyboardEvent.timeStamp in the browser console is calling Event::TimeStamp() instead of KeyboardEvent::TimeStamp. So we're apparently failing to properly override the Event::TimeStamp call.