All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=825257

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=f712d06bb14981d0e1d49ad0c4c20fbf7c765255f782afc3cd10c80f204ebb1b


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

pixel_xl

Is there a way to bisect the alerts?  The "Bisect" button was gray. Just want to make sure if it's an SPv175 issue.

Yes and no. It can't be bisected via the perf dashboard (yet) since the VR tests run outside of the normal perf lab, but we do have a bisect script for VR regressions in chrome/test/vr/auto_bisect.py. That's what I used to link the regressions to that CL. Below is the output from the bisect.

Bisecting: 30 revisions left to test after this (roughly 5 steps)
[f0d679acee3b86299df32df2f89d9edebde24e00] [Devtools] Compute large font threshold correctly for contrast ratio

=== Syncing to revision f0d679acee3b86299df32df2f89d9edebde24e00 and building ===
Syncing
Building
=== Isolating and running target vr_perf_tests ===
Isolating
Uploading
Running test
Got result 377352
=== Attempt 1 found that revision is GOOD ===
=== Current revision is GOOD ===
Bisecting: 15 revisions left to test after this (roughly 4 steps)
[d46ddaea180a3dec1671c752f3e5ffb3fc183ca0] Report was_cached in SubresourceLoadInfo

=== Syncing to revision d46ddaea180a3dec1671c752f3e5ffb3fc183ca0 and building ===
Syncing
Building
=== Isolating and running target vr_perf_tests ===
Isolating
Uploading
Running test
Got result 377400
=== Attempt 1 found that revision is GOOD ===
=== Current revision is GOOD ===
Bisecting: 7 revisions left to test after this (roughly 3 steps)
[c9963a068210f11fdfe9ae6ad56497a2ca449e9b] Add no-op triggers for optional and ANGLE tryservers.

=== Syncing to revision c9963a068210f11fdfe9ae6ad56497a2ca449e9b and building ===
Syncing
Building
=== Isolating and running target vr_perf_tests ===
Isolating
Uploading
Running test
Got result 377400
=== Attempt 1 found that revision is GOOD ===
=== Current revision is GOOD ===
Bisecting: 3 revisions left to test after this (roughly 2 steps)
[72b68bc867adc415dcd0ef70ba88ca27fb75ea6e] [vr] Fix voice search button colors

=== Syncing to revision 72b68bc867adc415dcd0ef70ba88ca27fb75ea6e and building ===
Syncing
Building
=== Isolating and running target vr_perf_tests ===
Isolating
Uploading
Running test
Got result 377400
=== Attempt 1 found that revision is GOOD ===
=== Current revision is GOOD ===
Bisecting: 1 revision left to test after this (roughly 1 step)
[63667eca2a1d86f5de61f29c7c5c6417cc351757] Add volume slider to UnifiedSystemTray.

=== Syncing to revision 63667eca2a1d86f5de61f29c7c5c6417cc351757 and building ===
Syncing
Building
=== Isolating and running target vr_perf_tests ===
Isolating
Uploading
Running test
Got result 377400
=== Attempt 1 found that revision is GOOD ===
=== Current revision is GOOD ===
Bisecting: 0 revisions left to test after this (roughly 0 steps)
[3a3c78a924a686ed0d3f90d765b00cdd78453e11] Reland "[SPv175] Enable SlimmingPaintV175 by default"

=== Syncing to revision 3a3c78a924a686ed0d3f90d765b00cdd78453e11 and building ===
Syncing
Building
=== Isolating and running target vr_perf_tests ===
Isolating
Uploading
Running test
Got result 390752
=== Attempt 1 found revision that is BAD ===
=== Current revision is BAD ===
3a3c78a924a686ed0d3f90d765b00cdd78453e11 is the first bad commit
commit 3a3c78a924a686ed0d3f90d765b00cdd78453e11
Author: Xianzhu Wang <wangxianzhu@chromium.org>
Date:   Thu Mar 15 02:49:49 2018 +0000

    Reland "[SPv175] Enable SlimmingPaintV175 by default"
    
    Enable SlimmingPaintV175 for M67
    
    Original change's description:
    > Revert "[SPv175] Enable SlimmingPaintV175 by default"
    >
    > This reverts commit 0a9a5c311a1d3a298f952e495510bd6fe3faa2f6.
    >
    > Reason for revert: We decided to delay the launch of SlimmingPaintV175
    > to M67, so that we have more time to fix the regressions.
    >
    > The revert CL is slightly modified so that later enabling/disabling of
    > SlimmingPaintV175 by default can just change one line in
    > content/public/common/content_features.cc (learnt from
    > RootLayerScrolling crrev/c/929662).
    >
    > Original change's description:
    > > [SPv175] Enable SlimmingPaintV175 by default
    > >
    > > SlimmingPaintV175 enables raster invalidation and paint chunks based
    > > on paint properties. See  crbug.com/771643 .
    > >
    > > Bug:  771643 
    > > Change-Id: I5fdbcabc7ca0f2fa8e69ae0fbf5a0077bba46cfe
    > > Reviewed-on: https://chromium-review.googlesource.com/923572
    > > Reviewed-by: Antoine Labour <piman@chromium.org>
    > > Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
    > > Cr-Commit-Position: refs/heads/master@{#537454}
    >
    > TBR=dgozman@chromium.org,wangxianzhu@chromium.org,chrishtr@chromium.org,piman@chromium.org
    >
    > # Not skipping CQ checks because original CL landed > 1 day ago.
    >
    > Bug:  771643 
    > Change-Id: I04177ada5d6b133fe47c0e0dbff42b6989f099ba
    > Reviewed-on: https://chromium-review.googlesource.com/938562
    > Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#539401}
    
    TBR=dgozman@chromium.org,wangxianzhu@chromium.org,chrishtr@chromium.org,piman@chromium.org
    
    # Not skipping CQ checks because original CL landed > 1 day ago.
    
    Bug:  771643 
    Change-Id: Ie64b80c21af02ed689d5c5b7489c5b32d94c0c11
    Reviewed-on: https://chromium-review.googlesource.com/947902
    Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
    Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#543291}

:040000 040000 31187766b4b561b93e35b15fcdefbcf962970c6e feb63ca50c5b609e4259e833aee4a27e6b56f258 M	content

Current status: the overall performance recovered: https://chromeperf.appspot.com/report?sid=2277ca22e46949fd62c383557ada94004688b493f66acfa42e2d92ff8ccd31a9&start_rev=540595&end_rev=553801. Different tests have different results. Some partly recovered, some fully recovered and some have progressions.