The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/91ec42827a81873f7e254959c0821b01ddcd4531

commit 91ec42827a81873f7e254959c0821b01ddcd4531
Author: yiyix <yiyix@chromium.org>
Date: Wed Jan 17 05:26:13 2018

Fix metric "Compositing.Display.Draw.Occlusion.Calculation.Time"

Logged metric name(Compositing.Display.Draw.Occlusion.Calculation.Time) doesn't
match histograms.xml metric name (Compositing.Display.Draw.Occlusion), so no
data is viewable on the dashboard. Updated the metric name in histograms.xml.

Note that the data for the metric is available, it's just not easily viewable
from the dashboard

Bug:  802122 
Change-Id: I3ca7c7e30f4fe42661fb19af51a4587081245aa1
Reviewed-on: https://chromium-review.googlesource.com/867271
Commit-Queue: Yi Xu <yiyix@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Yi Xu <yiyix@chromium.org>
Cr-Commit-Position: refs/heads/master@{#529623}
[modify] https://crrev.com/91ec42827a81873f7e254959c0821b01ddcd4531/tools/metrics/histograms/histograms.xml