Locking Windows Form Timers Event Handlers

[ivandrofly]

Hello Nick

I've noticed some timer handler method from SubtitleListView are using lock
before handling in event.

e.g: SubtitleEditListView.SyntaxColorLineTimerTick

Normally Windows Form Timer events are raised only on main-thread is there any particular reason for the lock?
Also consider that no other thread (beside the thread that created the control mostly main-thread) can access the control.