All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=844621

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=2b8840d9d4d5ff88decbebd84e6832f5b834d13dba4284c597c3104030996d40


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

chromium-rel-mac11-air
chromium-rel-mac11-pro
chromium-rel-mac12

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/101529b8240000

📍 Found a significant difference after 1 commit.
https://pinpoint-dot-chromeperf.appspot.com/job/101529b8240000

PresentationCallback:  trun on it for Mac by penghuang@chromium.org
https://chromium.googlesource.com/chromium/src/+/4cc26d55638bcfe501dfe25fc96c4110ff51bed6

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

Except draw-dynamic-webgl-to-hw-accelerated-canvas-2d, all others are expected results. To enable presentation feedback on Mac, we have to post one task per frame. The task is receive the presentation feedback in message loop. The task doesn't do any real work on Mac.

Issue 846062 has been merged into this issue.

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/16c24c7c240000

📍 Found a significant difference after 1 commit.
https://pinpoint-dot-chromeperf.appspot.com/job/16c24c7c240000

Reland "Use Skia's new simplified read/write pixels code paths" by bsalomon@chromium.org
https://chromium.googlesource.com/chromium/src/+/d74706673fcd86bc4c6fd6ff880f104379602ca9

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

One more task per frame is expected result.
For draw-dynamic-webgl-to-hw-accelerated-canvas-2d, it is caused by below change.

Reland "Use Skia's new simplified read/write pixels code paths" by bsalomon@chromium.org
https://chromium.googlesource.com/chromium/src/+/d74706673fcd86bc4c6fd6ff880f104379602ca9

So close this issue as wontfix. and will file a new one for draw-dynamic-webgl-to-hw-accelerated-canvas-2d regression.