All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=619018

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgvOKgpQoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgvNnpuwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg3LfyvwoM


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

chromium-rel-mac-hdd
chromium-rel-mac-retina
chromium-rel-mac11

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

Hi vmiura@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 : Speed up InvalidationRegion
Author  : vmiura
Commit description:
  
Staging invalidation rectangles in a vector allows us to skip building
a complex SkRegion for cases with many invalidations (> 256).  For cases
with fewer invalidations we will still build a full SkRegion.

R=enne@chromium.org
BUG= 606069 
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review-Url: https://codereview.chromium.org/2054473002
Cr-Commit-Position: refs/heads/master@{#398755}
Commit  : 62045ceab0fd83013d6cb781ba727d3d3ce68e18
Date    : Thu Jun 09 01:16:49 2016


===== TESTED REVISIONS =====
Revision         Mean      Std Dev     N  Good?
chromium@398754  0.784682  0.00394009  5  good
chromium@398755  0.961556  0.0045718   5  bad    <--
chromium@398756  0.972775  0.0109565   5  bad
chromium@398758  0.963652  0.00761282  5  bad
chromium@398762  0.960216  0.00483151  5  bad
chromium@398769  0.962736  0.00706751  5  bad

Bisect job ran on: mac_10_11_perf_bisect
Bug ID: 619018

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: 22.69%
Score: 99.9

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/mac_10_11_perf_bisect/builds/670
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9010235517177252256


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5854699559845888

| 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!

Oooh... this is actually a really good result!

The tests where raster_times_per_frame increased are text_constant_full_page_raster_*_pixels_per_second.  These tests scroll while continuously invalidating a long page of text.

Looking at the traces, the reason for the increase in rasterization is that we're now hitting main thread updates at 60fps instead of 30fps.  Total BeginMainFrame times dropped from ~18ms to ~8ms.  \o/

Deleted: trace-file-id_29-2016-06-08_17-42-42-63968-before.html 2.8 MB

trace-file-id_29-2016-06-08_17-42-42-63968-before.html 2.8 MB View Download

Deleted: trace-file-id_29-2016-06-08_23-43-03-9975-after.html 2.9 MB

trace-file-id_29-2016-06-08_23-43-03-9975-after.html 2.9 MB View Download

Nice :)

Closing as WontFix, as the thread time change is due to a large improvement in commit interval.