All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=855520

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=28dc972ec750e71a8304fa349ce2274687853b2cfbb1ff1193aef69b9797e083


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

linux-perf

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/1293d893240000

📍 Found significant differences after each of 3 commits.
https://pinpoint-dot-chromeperf.appspot.com/job/1293d893240000

Check for non-empty outline for U+0000..U+001F by behdad@behdad.org
https://chromium.googlesource.com/external/fontconfig/+/cd4043da0dfd61da73473b2f00d5e3a78ad13bec
0.04435 → 0.04488 (+0.00053)

Remove blanks facility from the library by behdad@behdad.org
https://chromium.googlesource.com/external/fontconfig/+/8f4c4d278d013f6cc69ba7d7bf0f8aed11398dfb
0.0448 → No values

Reland "Update fontconfig to 6cc99d6a" by thomasanderson@chromium.org
https://chromium.googlesource.com/chromium/src/+/0c91664fce2e753a65b04107ad24c7422691cf9d
No values → 0.0472

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

BULK EDIT

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.