All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=856067

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=873c4aa5e61e39a3c5afa045def97fae59658e8a7b725fc8e4daa2e325bafce2


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

health-plan-clankium-low-end-phone
health-plan-clankium-phone
perf-go-phone-1024
perf-go-phone-512

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8942758245172528048

=== Auto-CCing suspected CL author skobes@chromium.org ===

Hi skobes@chromium.org, the bisect results pointed to your CL, please take a look at the
results.


=== BISECT JOB RESULTS ===
Perf regression found with culprit

Suspected Commit
  Author : Steve Kobes
  Commit : 807c7cf898178b44c11866b69cf350da47f41b76
  Date   : Sat Jun 23 22:39:38 2018
  Subject: Remove ScrollableArea::IsScrollable and IsProgrammaticallyScrollable.

Bisect Details
  Configuration: clankium-phone-perf-bisect
  Benchmark    : system_health.memory_mobile
  Metric       : memory:chrome:all_processes:reported_by_chrome:cc:effective_size_avg/load_media/load_media_youtube
  Change       : 38.16% | 21552944.0 -> 29776640.0

Revision                                       Result                  N
android-chrome@6305b6474c                      21552944 +- 374357      6      good
android-chrome@e841561f09                      21634291 +- 557447      6      good
android-chrome@e841561f09,chromium@569891      21619456 +- 388103      6      good
android-chrome@e841561f09,chromium@569894      21628891 +- 560090      6      good
android-chrome@e841561f09,chromium@569895      21563744 +- 369534      6      good
android-chrome@e841561f09,chromium@569896      29853952 +- 239542      6      bad       <--
android-chrome@e841561f09,chromium@569897      30212912 +- 504941      6      bad
android-chrome@e841561f09,chromium@569902      29798240 +- 181590      6      bad
android-chrome@33d8f0dcc2                      29776640 +- 189375      6      bad

Please refer to the following doc on diagnosing memory regressions:
  https://chromium.googlesource.com/chromium/src/+/master/docs/memory-infra/memory_benchmarks.md

To Run This Test
  src/tools/perf/run_benchmark -v --browser=android-chrome --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests --story-filter=load.media.youtube system_health.memory_mobile

More information on addressing performance regressions:
  http://g.co/ChromePerformanceRegressions

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8942758245172528048


For feedback, file a bug with component Speed>Bisection

 Issue 856072  has been merged into this issue.

Investigating.

Issue 856106 has been merged into this issue.

Unable to repro locally but I see it on other bots like android-nexus5X:

https://chromeperf.appspot.com/report?sid=bb6630137c517d71fa7de6048141793588981aec410f798bc8b35be11efb665f

I'm testing some variations of the patch with perf try jobs to isolate the issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/28bed330b0acb7a7bc6d5eaffa029f8ebd150640

commit 28bed330b0acb7a7bc6d5eaffa029f8ebd150640
Author: Steve Kobes <skobes@chromium.org>
Date: Wed Jun 27 01:19:21 2018

Restore size check in CompositingReasonFinder.

This was removed in crrev.com/569896, causing significant memory
regressions in system health benchmarks on Android.

It's unclear why the similar size check in PLSA::UpdateScrollableAreaSet
(for computation of scrolls_overflow_) isn't sufficient.

Tested: perf try job
Bug:  856067 
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I0334f53d95ac1b4ddd9503b284ff880b8338ab67
Reviewed-on: https://chromium-review.googlesource.com/1115513
Commit-Queue: Steve Kobes <skobes@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570611}
[modify] https://crrev.com/28bed330b0acb7a7bc6d5eaffa029f8ebd150640/third_party/blink/renderer/core/paint/compositing/compositing_reason_finder.cc

 Issue 856355  has been merged into this issue.

Graphs are recovering.

 Issue 856359  has been merged into this issue.

 Issue 856838  has been merged into this issue.

 Issue 856359  has been merged into this issue.

 Issue 857081  has been merged into this issue.