All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=750851

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=8bb9743b00525a1265405f7c926115aeea21befce79dbfe8f5f2f69dcb2e7ba3


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

chromium-rel-mac-retina
chromium-rel-mac12

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8972521472206810816

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

Hi kenrb@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 : Ken Buchanan
  Commit : aaf6b58123e9bc49391a8f8cfe057b7c3269e9ef
  Date   : Thu Jul 27 15:46:12 2017
  Subject: Ensure overlapping compositor locks can time out

Bisect Details
  Configuration: mac_retina_perf_bisect
  Benchmark    : page_cycler_v2.basic_oopif
  Metric       : timeToFirstContentfulPaint_avg/pcv1-cold/http___booking.com
  Change       : 4.89% | 166.956785714 -> 175.121142857

Revision             Result                  N
chromium@489924      166.957 +- 37.4782      14      good
chromium@489937      165.539 +- 16.6991      9       good
chromium@489940      168.237 +- 28.7978      14      good
chromium@489941      165.733 +- 20.5031      9       good
chromium@489942      173.594 +- 20.0043      14      bad       <--
chromium@489943      188.397 +- 104.627      9       bad
chromium@489949      175.255 +- 22.8784      14      bad
chromium@489973      173.562 +- 20.7102      14      bad
chromium@490022      175.121 +- 28.6228      14      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 --story-filter=http...booking.com page_cycler_v2.basic_oopif

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8972521472206810816


For feedback, file a bug with component Speed>Bisection

Revert landed in r493671.

 Issue 750753  has been merged into this issue.