input: send touch frame event after up event

Currently the frame event gets lost: The touch focus is removed in the 'up' event. So the focus is gone when the frame event arrives so it is never sent to the clients.

To avoid this, keep the touch focus until the frame is handled.

I noticed this because chromium now waits for the frame event so touch does not work correctly any more (https://chromium-review.googlesource.com/c/chromium/src/+/3682560/6)