All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=624239

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg4vr0rAoM


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

chromium-rel-mac-retina

=== Auto-CCing suspected CL author wangxianzhu@chromium.org ===

Hi wangxianzhu@chromium.org, the bisect results pointed to your CL below as possibly
causing a regression. Please have a look at this info and see whether
your CL be related.


===== BISECT JOB RESULTS =====
Status: completed


===== SUSPECTED CL(s) =====
Subject : Disable DisplayItemClient aliveness checking when DCHECK is off
Author  : wangxianzhu
Commit description:
  
Only 1 crash report on 53.0.2777.0, and no crash reports after.
Disable the checking when DCHECK is off to unblock beta release
of m53.

BUG=609218

Review-Url: https://codereview.chromium.org/2104603002
Cr-Commit-Position: refs/heads/master@{#402372}
Commit  : 64a18013d7e52fe0372b97ac586e0ed652637bb0
Date    : Tue Jun 28 02:02:40 2016


===== TESTED REVISIONS =====
Revision         Mean      Std Dev     N  Good?
chromium@402350  0.713521  0.00594816  5  good
chromium@402362  0.712282  0.00254132  5  good
chromium@402368  0.715965  0.00448861  5  good
chromium@402371  0.711601  0.0076667   8  good
chromium@402372  0.729821  0.00658149  8  bad    <--
chromium@402373  0.726349  0.00701821  5  bad
chromium@402374  0.733177  0.00498136  5  bad

Bisect job ran on: mac_retina_perf_bisect
Bug ID: 624239

Test Command: src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --upload-results --also-run-disabled-tests thread_times.tough_scrolling_cases
Test Metric: thread_raster_cpu_time_per_frame/thread_raster_cpu_time_per_frame
Relative Change: 2.75%
Score: 99.0

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/mac_retina_perf_bisect/builds/1374
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9008557969435263424


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5777603902832640

| O O | Visit http://www.chromium.org/developers/speed-infra/perf-bug-faq
|  X  | for more information addressing perf regression bugs. For feedback,
| / \ | file a bug with component Tests>AutoBisect.  Thank you!

===== BISECT JOB RESULTS =====
Status: completed


===== SUSPECTED CL(s) =====
Subject : Disable DisplayItemClient aliveness checking when DCHECK is off
Author  : wangxianzhu
Commit description:
  
Only 1 crash report on 53.0.2777.0, and no crash reports after.
Disable the checking when DCHECK is off to unblock beta release
of m53.

BUG=609218

Review-Url: https://codereview.chromium.org/2104603002
Cr-Commit-Position: refs/heads/master@{#402372}
Commit  : 64a18013d7e52fe0372b97ac586e0ed652637bb0
Date    : Tue Jun 28 02:02:40 2016


===== TESTED REVISIONS =====
Revision         Mean      Std Dev     N  Good?
chromium@402350  0.710227  0.00702554  8  good
chromium@402362  0.710382  0.00625879  8  good
chromium@402368  0.715371  0.0033716   8  good
chromium@402371  0.712765  0.00573672  5  good
chromium@402372  0.734999  0.00572152  5  bad    <--
chromium@402373  0.735069  0.00582764  5  bad
chromium@402374  0.725872  0.00731984  8  bad

Bisect job ran on: mac_retina_perf_bisect
Bug ID: 624239

Test Command: src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --upload-results --also-run-disabled-tests thread_times.tough_scrolling_cases
Test Metric: thread_raster_cpu_time_per_frame/thread_raster_cpu_time_per_frame
Relative Change: 1.90%
Score: 99.9

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/mac_retina_perf_bisect/builds/1375
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9008557751323693984


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=6359892214939648

| O O | Visit http://www.chromium.org/developers/speed-infra/perf-bug-faq
|  X  | for more information addressing perf regression bugs. For feedback,
| / \ | file a bug with component Tests>AutoBisect.  Thank you!

===== BISECT JOB RESULTS =====
Status: completed


===== SUSPECTED CL(s) =====
Subject : Disable DisplayItemClient aliveness checking when DCHECK is off
Author  : wangxianzhu
Commit description:
  
Only 1 crash report on 53.0.2777.0, and no crash reports after.
Disable the checking when DCHECK is off to unblock beta release
of m53.

BUG=609218

Review-Url: https://codereview.chromium.org/2104603002
Cr-Commit-Position: refs/heads/master@{#402372}
Commit  : 64a18013d7e52fe0372b97ac586e0ed652637bb0
Date    : Tue Jun 28 02:02:40 2016


===== TESTED REVISIONS =====
Revision         Mean      Std Dev     N  Good?
chromium@402350  0.71323   0.00471464  5  good
chromium@402362  0.712069  0.00587758  5  good
chromium@402368  0.716458  0.00329925  8  good
chromium@402371  0.716967  0.00897285  8  good
chromium@402372  0.734146  0.00824548  8  bad    <--
chromium@402373  0.73435   0.00465899  8  bad
chromium@402374  0.731339  0.00525416  8  bad

Bisect job ran on: mac_retina_perf_bisect
Bug ID: 624239

Test Command: src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --upload-results --also-run-disabled-tests thread_times.tough_scrolling_cases
Test Metric: thread_raster_cpu_time_per_frame/thread_raster_cpu_time_per_frame
Relative Change: 2.36%
Score: 99.9

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/mac_retina_perf_bisect/builds/1373
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9008558036598362080


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5840790119514112

| O O | Visit http://www.chromium.org/developers/speed-infra/perf-bug-faq
|  X  | for more information addressing perf regression bugs. For feedback,
| / \ | file a bug with component Tests>AutoBisect.  Thank you!

The CL only reduces operations during painting. Perhaps the rasterize cpu time increases just because some low level measurement error caused by reduced main thread cpu usage.