io/router: [API] drop extra frame

This change removes the extra frame scheduled when events was delivered
during a frame. This extra frame was intended to paper over state changes
that happen later than the layout depending on it.

However, it is better for programs to never allow such state change skew,
and recent changes allows them to refresh and query state before layout.

This is an API change because programs may rely on the extra frames.
Those programs should ensure that state is updated before relying on it
in layout.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

io/router/pointer_test.go

@@ -33,11 +33,6 @@ func TestPointerWakeup(t *testing.T) {
 	}
 	// However, adding a handler queues a Cancel event.
 	assertEventPointerTypeSequence(t, r.Events(handler), pointer.Cancel)
-	// Verify that r.Events does trigger a redraw.
-	r.Frame(&ops)
-	if _, wake := r.WakeupTime(); !wake {
-		t.Errorf("pointer.Cancel event didn't trigger a redraw")
-	}
 }
 
 func TestPointerDrag(t *testing.T) {