Bug 1807812 - Remove WidgetEventTime::mTime, r=masayuki,geckoview-reviewers,m_kato

HTMLSelectEventListener changes are needed, since currently that code works somewhat by accident given that
mTime often contains totally bogus values, like PR_IntervalNow(). Those changes then reveal issues also in
browser_editAddressDialog.js.

Differential Revision: https://phabricator.services.mozilla.com/D165618

layout/base/PresShell.cpp

@@ -5858,7 +5858,6 @@ void PresShell::ProcessSynthMouseMoveEvent(bool aFromScroll) {
                          WidgetMouseEvent::eSynthesized);
   event.mRefPoint =
       LayoutDeviceIntPoint::FromAppUnitsToNearest(refpoint, viewAPD);
-  event.mTime = PR_IntervalNow();
   // XXX set event.mModifiers ?
   // XXX mnakano I think that we should get the latest information from widget.