The task IDs being posted in the trace are: OMAHA_JOB_ID, NOTIFICATION_SERVICE_JOB_ID. Disabling tasks for benchmarking should not break anything because Android scheduling could realistically delay them for longer than the benchmark duration. Preferably we should ignore all tasks to avoid surprises like this in the future.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9afce6048cbb4d737604ae1356a98876d5fbeaed

commit 9afce6048cbb4d737604ae1356a98876d5fbeaed
Author: Egor Pasko <pasko@chromium.org>
Date: Fri Sep 28 19:55:19 2018

BackgroundTaskScheduler: allow ignoring jobs for benchmarking

Introduce a commandline flag --ignore-background-tasks that would be set
by Telemetry when running startup benchmarks to avoid random tasks from
caching the process and skewing the metrics that are based on process
creation.

The bug has an example trace and more details.

Bug:  890424 
Change-Id: I456e0f15406ebba7c930f8ec445da0759e9a087d
Reviewed-on: https://chromium-review.googlesource.com/1252382
Reviewed-by: Filip Gorski <fgorski@chromium.org>
Commit-Queue: Egor Pasko <pasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595188}
[modify] https://crrev.com/9afce6048cbb4d737604ae1356a98876d5fbeaed/components/background_task_scheduler/android/java/src/org/chromium/components/background_task_scheduler/BackgroundTaskSchedulerImpl.java

The following revision refers to this bug:
  https://chromium.googlesource.com/catapult/+/ad0631532d0cb16d2a72465147a5a8142ad0919a

commit ad0631532d0cb16d2a72465147a5a8142ad0919a
Author: Egor Pasko <pasko@chromium.org>
Date: Mon Oct 01 15:17:05 2018

Avoid running Android background jobs

**PERF SHERIFFS**: this should move metrics on Android. Likely startup,
                   but there could be something else affected, like
                   loading.

Use the newly introduced flag in http://crrev.com/595188 to prevent
spurious jobs from being created when benchmarking. Those jobs do
little, but lead to Chrome process being cached, which artificially
inflates the metrics that are based on process start.

This should cut down those occasional stdev of 2 seconds. The bugs
provide more context.

Bug:  chromium:890424 
Bug:  chromium:881384 
Change-Id: Ifb599bff0e55041495aa87983262dfd0940df226
Reviewed-on: https://chromium-review.googlesource.com/1254101
Commit-Queue: Egor Pasko <pasko@chromium.org>
Reviewed-by: Juan Antonio Navarro Pérez <perezju@chromium.org>

[modify] https://crrev.com/ad0631532d0cb16d2a72465147a5a8142ad0919a/telemetry/telemetry/internal/backends/chrome/chrome_startup_args.py

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fc8fe0364d1fa8c20e308567a0d1a4340d27e046

commit fc8fe0364d1fa8c20e308567a0d1a4340d27e046
Author: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Date: Mon Oct 01 22:31:14 2018

Roll src/third_party/catapult ac93684421fa..69f64b270397 (4 commits)

https://chromium.googlesource.com/catapult.git/+log/ac93684421fa..69f64b270397


git log ac93684421fa..69f64b270397 --date=short --no-merges --format='%ad %ae %s'
2018-10-01 oysteine@google.com Allow bindId for separate begin/end slices as well
2018-10-01 simonhatch@chromium.org Dashboard - Create histograms per bot for alert statistics
2018-10-01 cbruni@chromium.org [pinpoint] Redirect to raw results.html on job completion
2018-10-01 pasko@chromium.org Avoid running Android background jobs


Created with:
  gclient setdep -r src/third_party/catapult@69f64b270397

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:890025 ,chromium:876233, chromium:890424 , chromium:881384 
TBR=sullivan@chromium.org

Change-Id: I3fa5e360f1c7c98152f5078c58d9d41e34b66ebc
Reviewed-on: https://chromium-review.googlesource.com/1254685
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@{#595601}
[modify] https://crrev.com/fc8fe0364d1fa8c20e308567a0d1a4340d27e046/DEPS