The reason this is purple is that 
"shard #0 had an internal swarming failure": 

https://chrome-swarming.appspot.com/user/task/415a76ef6273a710
https://chrome-swarming.appspot.com/user/task/41694be723f26b10

It looks like this is what is running on shard 0:

    "0": {
        "benchmarks": {
            "blink_perf.accessibility": {},
            "blink_perf.bindings": {},
            "blink_perf.canvas": {},
            "blink_perf.css": {},
            "blink_perf.dom": {},
            "blink_perf.events": {},
            "blink_perf.image_decoder": {},
            "blink_perf.layout": {
                "end": 62
            }
        }
    },

The reason we got an internal swarming failure is that the BOT_DIED.

The last test that started was

[ RUN      ] blink_perf.canvas/upload-canvas-2d-to-texture.html
on one of them and
[ RUN      ] blink_perf.canvas/docs-paper_RAF.html?RAF
on the other one.

One recent change was https://chromium-review.googlesource.com/c/chromium/src/+/1300038

Docs should be at https://bit.ly/blink-perf-benchmarks

Aaron, can you please take a look?

Yeah, I see this started happening on Nov 9th after that CL was submitted: https://ci.chromium.org/p/chrome/builders/luci.chrome.ci/mac-10_13_laptop_high_end-perf/1831

on Nov 8th the bot was not being killed: https://ci.chromium.org/p/chrome/builders/luci.chrome.ci/mac-10_13_laptop_high_end-perf/1813

I will revert https://chromium-review.googlesource.com/c/chromium/src/+/1300038

Reverting in https://chromium-review.googlesource.com/c/chromium/src/+/1351460

Merge conflict on the revert. I will do it manually.

I can't seem to find any log showing the crashes.

I think it would be much better to disable the particular crashing tests rather than reverting the CL, specially because those crashes are from regular HTML files, which shouldn't be crashing to begin with.

I would be happy to disable only the particular crashing tests if I knew which ones they were.

Usually the safe way to fix this type of problem is to revert changes to get back to a good state and then we can re-add from there.

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/1696c680140000

📍 Job complete. See results below.
https://pinpoint-dot-chromeperf.appspot.com/job/1696c680140000

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9743711118a17c45ee2e866635271751dac0b9e2

commit 9743711118a17c45ee2e866635271751dac0b9e2
Author: Caleb Rouleau <crouleau@chromium.org>
Date: Mon Nov 26 23:28:19 2018

Revert "Add RAF tests to blink_perf.canvas benchmark."

This reverts commit 7149ab705c9a7c1c9c57c960c05e2de216680c7d.
https://chromium-review.googlesource.com/c/chromium/src/+/1300038

TBR=nednguyen@google.com

Bug: 908515
Change-Id: I08a2b7adbf9fa20c8ccc2d8b6573981f0828c12d
Reviewed-on: https://chromium-review.googlesource.com/c/1351501
Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Commit-Queue: Caleb Rouleau <crouleau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610974}
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/docs/speed/benchmark/harnesses/blink_perf.md
[delete] https://crrev.com/1ac2b95d87558cb9f13af9eaf11b81b3fc98fb06/third_party/blink/perf_tests/canvas/OWNERS
[delete] https://crrev.com/1ac2b95d87558cb9f13af9eaf11b81b3fc98fb06/third_party/blink/perf_tests/canvas/gpu-bound-shader.html
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/third_party/blink/perf_tests/canvas/resources/canvas_runner.js
[delete] https://crrev.com/1ac2b95d87558cb9f13af9eaf11b81b3fc98fb06/third_party/blink/perf_tests/canvas/sheets-render.html
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/third_party/blink/perf_tests/canvas/upload-webgl-to-texture.html
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/benchmark.csv
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/benchmarks/blink_perf.py
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/contrib/blink_layoutng_perf/blink_layoutng_perf.py
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/contrib/blink_perf_cmdline/blink_perf_cmdline.py
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/contrib/blink_perf_xml_http_request/blink_perf_xml_http_request.py
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/android-go-perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/android-go_webview-perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/android-nexus5x-perf-fyi_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/android-nexus5x-perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/android-pixel2-perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/android-pixel2_webview-perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/android_nexus5_perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/android_nexus5x_webview_perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/android_nexus6_webview_perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/linux-perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/mac-10_12_laptop_low_end-perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/mac-10_13_laptop_high_end-perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/win-10-perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/win_7_nvidia_gpu_perf_map.json
[modify] https://crrev.com/9743711118a17c45ee2e866635271751dac0b9e2/tools/perf/core/shard_maps/win_7_perf_map.json

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/11ccfc67e40000

📍 Job complete. See results below.
https://pinpoint-dot-chromeperf.appspot.com/job/11ccfc67e40000

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/1167d5ec140000

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/1789fb38140000

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/109d177fe40000

this build https://ci.chromium.org/p/chrome/builders/luci.chrome.ci/mac-10_13_laptop_high_end-perf/1948 is right after my revert went through, and on it we do get a BOT_DIED on shard #16
and this one as well: https://ci.chromium.org/p/chrome/builders/luci.chrome.ci/mac-10_13_laptop_high_end-perf/1949
For this one it goes back to shard #1: https://ci.chromium.org/p/chrome/builders/luci.chrome.ci/mac-10_13_laptop_high_end-perf/1950
same with 1951
but then https://ci.chromium.org/p/chrome/builders/luci.chrome.ci/mac-10_13_laptop_high_end-perf/1952 is fully passing
so I'm not sure what happened


One thing I'm wondering about is what causes BOT_DIED.
from here https://godoc.org/go.chromium.org/luci/milo/buildsource/swarming :

    // TaskBotDied means task started but bot died.
    TaskBotDied = "BOT_DIED"

📍 Job complete. See results below.
https://pinpoint-dot-chromeperf.appspot.com/job/109d177fe40000

📍 Job complete. See results below.
https://pinpoint-dot-chromeperf.appspot.com/job/1789fb38140000

📍 Job complete. See results below.
https://pinpoint-dot-chromeperf.appspot.com/job/1167d5ec140000

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/1567d5ec140000

📍 Job complete. See results below.
https://pinpoint-dot-chromeperf.appspot.com/job/1567d5ec140000

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5a62b2300ab9c19b87a20631c9198022406f91d7

commit 5a62b2300ab9c19b87a20631c9198022406f91d7
Author: Aaron Krajeski <aaronhk@google.com>
Date: Tue Nov 27 20:49:59 2018

Add an app test and a gpu-bound test to blink_perf.canvas tests

https://chromium-review.googlesource.com/c/chromium/src/+/1351501 has
reverted some perf changes due to high-end mac laptops crashing. Re-add
that CL piece by piece, starting here.

Re-add 2 tests: a render of google-sheets and an intense shader-based
test that will be GPU bound.

Bug: 908515
Change-Id: I2d371c1db7e5e1502367fb7c2093f4ec521f3b62
Reviewed-on: https://chromium-review.googlesource.com/c/1352339
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Commit-Queue: Aaron Krajeski <aaronhk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611303}
[add] https://crrev.com/5a62b2300ab9c19b87a20631c9198022406f91d7/third_party/blink/perf_tests/canvas/OWNERS
[add] https://crrev.com/5a62b2300ab9c19b87a20631c9198022406f91d7/third_party/blink/perf_tests/canvas/gpu-bound-shader.html
[add] https://crrev.com/5a62b2300ab9c19b87a20631c9198022406f91d7/third_party/blink/perf_tests/canvas/sheets-render.html