All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=747923

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=76e5b3a43520e4d3cfc217b87d36324be7c1142d54d1bea283e6df825d36f114


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

android-webview-nexus5X

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8973189745333216000

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

Hi ulan@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 : Ulan Degenbaev
  Commit : 973314f2e1d00831dd525e2214aacf5fb6c86ecb
  Date   : Tue Jul 18 18:03:19 2017
  Subject: Revert "[runtime] Copy descriptors on prototype map transition."

Bisect Details
  Configuration: android_webview_arm64_aosp_perf_bisect
  Benchmark    : memory.top_10_mobile
  Metric       : memory:webview:all_processes:reported_by_chrome:v8:effective_size_avg/foreground/http_m_intl_taobao_com_group_purchase_html
  Change       : 3.24% | 5794213.14286 -> 5981990.28571

Revision                           Result                  N
chromium@487633                    5794213 +- 492065       14      good
chromium@487649                    5762697 +- 253356       6       good
chromium@487657                    5734401 +- 278848       6       good
chromium@487661                    5749371 +- 204097       6       good
chromium@487662                    5738840 +- 289430       9       good
chromium@487662,v8@21a66b11d3      5776711 +- 248569       6       good
chromium@487662,v8@973314f2e1      5992221 +- 47261.7      6       bad       <--
chromium@487662,v8@e825c4318e      6002325 +- 348280       9       bad
chromium@487663                    5991661 +- 255188       6       bad
chromium@487665                    5991567 +- 276295       14      bad
chromium@487697                    5981990 +- 522114       14      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-webview --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests memory.top_10_mobile

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8973189745333216000


For feedback, file a bug with component Speed>Bisection

The culprit CL is a revert of another CL.

 Issue 748522  has been merged into this issue.