All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=757333

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=d722b4ae4b44d56754fa66735e4ee55798dbd75e4a1481dbeb9f9104fe68bf27


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

chromium-rel-mac11-air

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8970675645021519120

=== BISECT JOB RESULTS ===
Perf regression found but unable to narrow commit range

Build failures prevented the bisect from narrowing the range further.


Bisect Details
  Configuration: mac_air_perf_bisect
  Benchmark    : media.tough_video_cases_tbmv2
  Metric       : memory:chrome:browser_process:reported_by_chrome:tracing:effective_size_avg/video.html?src_crowd1080.webm
  Change       : 0.90% | 67051632.0 -> 67656904.0

Suspected Commit Range
  3 commits in range
  https://chromium.googlesource.com/chromium/src/+log/2a6a10e21f32182d55c207c3f71e8f3f625f697b..d54c0c1eccbddf90ea69bd14ca1290d721eee9b9


Revision             Result                   N
chromium@490303      67051632 +- 319861       6        good
chromium@491177      66844587 +- 743163       6        good
chromium@491613      67097852 +- 253230       6        good
chromium@491831      67059203 +- 1212287      14       good
chromium@491845      67072081 +- 673429       9        good
chromium@491852      67037573 +- 452676       6        good
chromium@491855      67073513 +- 971137       14       good
chromium@491857      67124743 +- 1267339      14       good
chromium@491858      ---                      ---      build failure
chromium@491859      ---                      ---      build failure
chromium@491860      67530663 +- 814132       14       bad
chromium@491886      67326659 +- 933409       14       bad
chromium@491940      67643078 +- 924872       9        bad
chromium@492049      67656904 +- 332541       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 --story-filter=video.html.src.crowd1080.webm 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/8970675645021519120


For feedback, file a bug with component Speed>Bisection

of the three commits, yours seems to be the only one that's specific to mac.

Same as  issue 760566 . Nothing to be done since this is 10.11-only as a workaround for kernel panics.