LoAF: count tasks with UI events towards blockingDuration

Apparently UI events are sent in a task that's not associated with a frame (using the input task source), so the AnimationFrameTimingMonitor thought that it was a task unrelated to the current widget.

Fixed by applying the task duration if this task produced any UI events.

Bug: 1501836 Change-Id: I482ada6850e0b97e7e1fc6237e75905881017587 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5033867 Reviewed-by: Michal Mocny mmocny@chromium.org Commit-Queue: Noam Rosenthal nrosenthal@chromium.org Cr-Original-Commit-Position: refs/heads/main@{#1225647} Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5039591 Cr-Commit-Position: refs/heads/main@{#1226100}