The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/772b2bcdbaa8ea5c5b1f47255c6c1562016fb680

commit 772b2bcdbaa8ea5c5b1f47255c6c1562016fb680
Author: Christian Biesinger <cbiesinger@chromium.org>
Date: Tue Jan 30 06:03:38 2018

Revert "Add UKM metrics for rendering timing measurements"

This reverts commit a324bac1171a6d35eb9fe367529300aabc3ae1f2.

Reason for revert: Causes various performance regressions and at least one memory regression, see bugs listed below.

Original change's description:
> Add UKM metrics for rendering timing measurements
>
> UKM review: https://docs.google.com/document/d/1Cpe5kLi3tVshH3evoJVUVDjOw7le-f8jFwBjEk2uadY/edit
>
> Bug: 783383
> Change-Id: Ib684e9e07322e27633b33576c688fa699fada81e
> Reviewed-on: https://chromium-review.googlesource.com/812154
> Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
> Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
> Commit-Queue: Christian Biesinger <cbiesinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#532051}

TBR=cbiesinger@chromium.org,asvitkine@chromium.org,chrishtr@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 783383, 807121 , 806814 , 806810 , 806808 , 806806 , 806795 , 806801 , 806809 , 806812 , 806830 , 806829 , 806805 , 806796 
Change-Id: I33e40eb337bb0b1daea4be753878d7218342942f
Reviewed-on: https://chromium-review.googlesource.com/892482
Commit-Queue: Christian Biesinger <cbiesinger@chromium.org>
Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532789}
[modify] https://crrev.com/772b2bcdbaa8ea5c5b1f47255c6c1562016fb680/services/metrics/public/cpp/ukm_recorder.h
[modify] https://crrev.com/772b2bcdbaa8ea5c5b1f47255c6c1562016fb680/third_party/WebKit/Source/core/frame/LocalFrameView.cpp
[modify] https://crrev.com/772b2bcdbaa8ea5c5b1f47255c6c1562016fb680/third_party/WebKit/Source/core/frame/LocalFrameView.h
[modify] https://crrev.com/772b2bcdbaa8ea5c5b1f47255c6c1562016fb680/tools/metrics/ukm/ukm.xml

Affected metrics returned to previous values after the revert. Thanks!