All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=783785

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=d0ee4550ab9a6be6cec270f98315983dc85107f4fcb87127e7e74ecdd688d2e8


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

chromium-rel-win7-x64-dual

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8963300514301580928

=== BISECT JOB RESULTS ===
NO Perf regression found

Bisect Details
  Configuration: win_x64_perf_bisect
  Benchmark    : smoothness.tough_canvas_cases
  Metric       : frame_times/http___www.craftymind.com_factory_guimark2_HTML5ChartingTest.html

Revision             Result                  N
chromium@515063      18.8191 +- 1.94023      21      good
chromium@515124      18.8362 +- 1.88013      21      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 --story-filter=http...www.craftymind.com.factory.guimark2.HTML5ChartingTest.html smoothness.tough_canvas_cases

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8963300514301580928


For feedback, file a bug with component Speed>Bisection

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/164fa1cef80000

📍 Found a significant difference after 1 commit.
https://pinpoint-dot-chromeperf.appspot.com/job/164fa1cef80000

Reland: Refactor of Canvas2DLayerBridge resource model
By junov@chromium.org · Wed Nov 08 23:26:00 2017
chromium @ 5b07996e178c5f4e153e771d48ab839867fa7440

Understanding performance regressions:
  http://g.co/ChromePerformanceRegressions

junov: ping on this regression? It hasn't recovered.

The culprit CL is: https://chromium-review.googlesource.com/c/chromium/src/+/728340

This change modified performance characteristics of 2D canvas. Overall it was a good change.  This is the only test that saw a measurable regression (on only one platform), and almost all other tests got a performance improvement.

Let's take this as a positive trade-off