I found some blink_perf.accessibility alerts whose ownership.component is a list instead of a string.
https://chromium-review.googlesource.com/c/chromium/src/+/1234325/

I'll patch the chromeperf dashboard to work around them temporarily, add a typecheck to the benchmark.Info decorator, and fix the benchmark.
https://chromium-review.googlesource.com/c/catapult/+/1323853
https://chromium-review.googlesource.com/c/chromium/src/+/1323801

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ee2daf8a3cf1c8f914fe16cc85d9f0b251b5b986

commit ee2daf8a3cf1c8f914fe16cc85d9f0b251b5b986
Author: Ben Hayden <benjhayden@chromium.org>
Date: Thu Nov 08 00:05:22 2018

Fix blink_perf.accessibility component.

component is a singular string, not a list.

Bug: chromium:902796
Change-Id: I0efd7f9eec2fb88173225ea4f597e8687fa9ee3a
Reviewed-on: https://chromium-review.googlesource.com/c/1323801
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Commit-Queue: Ben Hayden <benjhayden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606234}
[modify] https://crrev.com/ee2daf8a3cf1c8f914fe16cc85d9f0b251b5b986/tools/perf/benchmark.csv
[modify] https://crrev.com/ee2daf8a3cf1c8f914fe16cc85d9f0b251b5b986/tools/perf/benchmarks/blink_perf.py

The following revision refers to this bug:
  https://chromium.googlesource.com/catapult/+/a273b256b8de878ba9218ccee0f7adfdba5e5b77

commit a273b256b8de878ba9218ccee0f7adfdba5e5b77
Author: Ben Hayden <benjhayden@chromium.org>
Date: Wed Nov 14 20:20:43 2018

Temporarily permit alerts to have lists of ownership components.

The blink_perf.accessibility benchmark seems to have uploaded some malformed
data that caused an error.
This CL also adds a typecheck to telemetry's Info decorator to prevent this
kind of bug from recurring.

Bug: chromium:902796
Change-Id: I5304a4b967a685f118bcd6a56bbc7d2e824ee116
Reviewed-on: https://chromium-review.googlesource.com/c/1323853
Commit-Queue: Ben Hayden <benjhayden@chromium.org>
Reviewed-by: Dave Tu <dtu@chromium.org>

[modify] https://crrev.com/a273b256b8de878ba9218ccee0f7adfdba5e5b77/dashboard/dashboard/find_anomalies.py
[modify] https://crrev.com/a273b256b8de878ba9218ccee0f7adfdba5e5b77/dashboard/dashboard/file_bug.py

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0e55d4452afdab2949faf5141aac8224626bcefc

commit 0e55d4452afdab2949faf5141aac8224626bcefc
Author: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Date: Wed Nov 14 22:03:43 2018

Roll src/third_party/catapult 35d4c6c88f92..4925b069e1cf (6 commits)

https://chromium.googlesource.com/catapult.git/+log/35d4c6c88f92..4925b069e1cf


git log 35d4c6c88f92..4925b069e1cf --date=short --no-merges --format='%ad %ae %s'
2018-11-14 benjhayden@chromium.org Add polymer-svg-template to third_party for v2spa
2018-11-14 benjhayden@chromium.org Temporarily permit alerts to have lists of ownership components.
2018-11-14 benjhayden@chromium.org Add triage-existing for v2spa
2018-11-14 benjhayden@chromium.org Disable telemetry tests that fail on Luci Android.
2018-11-14 benjhayden@chromium.org Add timeseries-descriptor for v2spa
2018-11-14 benjhayden@chromium.org Fix timestamp x-axis in V1 charts.


Created with:
  gclient setdep -r src/third_party/catapult@4925b069e1cf

The AutoRoll server is located here: https://autoroll.skia.org/r/catapult-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

CQ_INCLUDE_TRYBOTS=luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel

BUG=chromium:902796,chromium:886940
TBR=sullivan@chromium.org

Change-Id: I8a8237f8cdfe354329d1e4e99cb5894f17300e2f
Reviewed-on: https://chromium-review.googlesource.com/c/1336215
Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#608138}
[modify] https://crrev.com/0e55d4452afdab2949faf5141aac8224626bcefc/DEPS