All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=783656

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=7720d3d040207581660e733859906443cde9f764d30cb554aaebdb65c48aacfa


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

chromium-rel-win7-gpu-ati

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8963323082306639904

=== 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: winx64ati_perf_bisect
  Benchmark    : memory.long_running_idle_gmail_background_tbmv2
  Metric       : v8-gc-latency-mark-compactor_avg/v8-gc-latency-mark-compactor_avg
  Change       : 46.91% | 33.2845309524 -> 21.357702381

Suspected Commit Range
  6 commits in range
  https://chromium.googlesource.com/chromium/src/+log/5c8dc03ef7b61d9f3af7b8bee3266910cd397f15..f5be521c4c2a56eecfe3228b2ba3997b0347b809


Revision             Result                  N
chromium@514493      33.2845 +- 38.6246      14       good
chromium@514530      33.0284 +- 49.752       20       good
chromium@514569      34.4071 +- 59.6762      20       good
chromium@514582      32.4812 +- 38.9777      14       good
chromium@514585      34.8812 +- 40.0102      14       good
chromium@514586      ---                     ---      build failure
chromium@514587      ---                     ---      build failure
chromium@514588      ---                     ---      build failure
chromium@514589      ---                     ---      build failure
chromium@514590      ---                     ---      build failure
chromium@514591      21.7579 +- 2.8019       5        bad
chromium@514593      21.3577 +- 35.5577      14       bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=release_x64 --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests memory.long_running_idle_gmail_background_tbmv2

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8963323082306639904


For feedback, file a bug with component Speed>Bisection

Looks like it's reverted to the previous average.