All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=757339

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=36776a384614b779b0874cdf5ac01d72084f018a8a7a7cdfa6709380e6f9646e


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

chromium-rel-mac11
chromium-rel-mac12

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8970675402578997120

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

Hi ssid@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 : Siddhartha
  Commit : e241d0ac5772386e8b7e8016c99c0ac5d07e8dcb
  Date   : Fri Aug 18 23:11:02 2017
  Subject: Memory-infra: Remove use of unique tracing ID and add resident size to discardable dumps

Bisect Details
  Configuration: mac_10_12_perf_bisect
  Benchmark    : media.tough_video_cases_tbmv2
  Metric       : memory:chrome:all_processes:reported_by_chrome:discardable:effective_size_avg/memory:chrome:all_processes:reported_by_chrome:discardable:effective_size_avg

Revision             Result                  N
chromium@495705      0.0 +- 0.0              6      good
chromium@495726      0.0 +- 0.0              6      good
chromium@495729      0.0 +- 0.0              6      good
chromium@495731      0.0 +- 0.0              6      good
chromium@495732      9784.89 +- 3601.57      6      bad       <--
chromium@495737      9642.67 +- 1045.12      6      bad
chromium@495747      9699.56 +- 1415.95      6      bad
chromium@495789      10296.9 +- 2246.93      6      bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests media.tough_video_cases_tbmv2

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8970675402578997120


For feedback, file a bug with component Speed>Bisection

 Issue 758330  has been merged into this issue.

The 10-50KB regression is expected since we now have better metrics to measure discardable memory size.
WAI.