All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=776398

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=c18281627a81a9b00d400a99ccc15751da82b1e0a61757bcfdb24b4f19e79ecd


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

chromium-rel-mac11

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8965291770882277168

=== BISECT JOB RESULTS ===
Perf regression found with culprit

Suspected Commit
  Author : Robert Phillips
  Commit : 7f9b215695aae262797758b2e2a7b1d35fbe584f
  Date   : Thu Oct 12 13:42:01 2017
  Subject: Force all Intel GPUs to use draws instead of clears on Macs

Bisect Details
  Configuration: mac_10_11_perf_bisect
  Benchmark    : blink_perf.canvas
  Metric       : transferFromImageBitmap/transferFromImageBitmap
  Change       : 28.40% | 32936.9079771 -> 23581.4333189

Revision                             Result                  N
chromium@508763                      32936.9 +- 1957.16      6      good
chromium@508825                      32863.2 +- 1491.85      6      good
chromium@508833                      33066.6 +- 2039.24      6      good
chromium@508837                      32763.7 +- 2027.06      6      good
chromium@508839                      33103.3 +- 1843.33      6      good
chromium@508839,skia@7f9b215695      23494.0 +- 1257.7       6      bad       <--
chromium@508839,skia@5698c8a8a0      22991.9 +- 1533.73      6      bad
chromium@508839,skia@cd975d5aa5      23028.1 +- 1179.22      6      bad
chromium@508839,skia@1ba5b6baa8      23494.0 +- 3434.81      6      bad
chromium@508839,skia@18e5cbbe65      22942.4 +- 1382.28      6      bad
chromium@508839,skia@8efb9c5e82      23187.9 +- 1292.39      6      bad
chromium@508840                      25116.8 +- 5713.42      6      bad
chromium@508841                      22984.2 +- 1327.05      6      bad
chromium@508856                      24074.0 +- 3838.06      6      bad
chromium@508887                      23581.4 +- 5121.91      6      bad

Please refer to the following doc on diagnosing blink_perf regressions:
  https://chromium.googlesource.com/chromium/src/+/master/docs/speed/benchmark_harnesses/blink_perf.md

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

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8965291770882277168


For feedback, file a bug with component Speed>Bisection