GitLab

This CL drops clamping for long tasks to improve accuracy.
Discussion at https://github.com/w3c/longtasks/issues/29

Bug: chromium:681718
Change-Id: If6df344f0203f7b6347f54ffa49be8d6689b7d71
Reviewed-on: https://chromium-review.googlesource.com/587590Reviewed-by: Shubhie Panicker <panicker@chromium.org>
Reviewed-by: Steve Kobes <skobes@chromium.org>
Commit-Queue: Nicolás Peña <npm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491166}