All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=866555

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=a5a1e3cc8e4b5e1a5d47a09e194b8477f798488a79d12c77ab8451308d64b5c6


Bot(s) for this bug's original alert(s):

mojo-linux-perf

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/13e42e69a40000

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/14e3ab4da40000

😿 Pinpoint job stopped with an error.
https://pinpoint-dot-chromeperf.appspot.com/job/13e42e69a40000

All of the runs failed. The most common error (7/20 runs) was:
  Run at /b/s/w/ir/third_party/Traceback (most recent call last):

📍 Found significant differences after each of 2 commits.
https://pinpoint-dot-chromeperf.appspot.com/job/14e3ab4da40000

Remove blanks facility from the library by behdad@behdad.org
https://chromium.googlesource.com/external/fontconfig/+/8f4c4d278d013f6cc69ba7d7bf0f8aed11398dfb
322 → No values

Reland "Reland "Update fontconfig to 6cc99d6a"" by thomasanderson@chromium.org
https://chromium.googlesource.com/chromium/src/+/a0c1584a2fade0146b7cd3380abe42feda02ad7c
No values → 193.5

Understanding performance regressions:
  http://g.co/ChromePerformanceRegressions

Original fontconfig roll introduced a bug:
https://chromium.googlesource.com/chromium/src/+/a0c1584a2fade0146b7cd3380abe42feda02ad7c

Subsequent fontconfig roll fixed the regression introduced in the previous roll:
https://chromium.googlesource.com/chromium/src/+/a0c1584a2fade0146b7cd3380abe42feda02ad7c

The graphs indicate a performance improvement on the original roll that introduced the bug, and a regression after.  These performance differences are expected due to the nature of the bug introduced and then fixed.

thomasanderson@ Thanks for the update and sorry for bringing up this issue again :)

Issue 866719 has been merged into this issue.