Edge also doesn't have this API. Our TODO links to this spec change:
https://github.com/w3c/hr-time/commit/39aaf81e1ea206fdf0fde4f49604ddd64d4f5b13

There's another workerStart both in Blink and the spec, relationship unclear:
https://w3c.github.io/resource-timing/#resources-included

Ilya can you advise here?

Removed from the spec? AFAIK, no: https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-workerstart

Mozilla hasn't implemented it yet: https://bugzilla.mozilla.org/show_bug.cgi?id=1191943

I believe everything is as expected on our end and we can close this.

https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-workerstart is the attribute on PerformanceResourceTiming, while this issue is about an attribute by the same name on SharedWorker:
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/timing/SharedWorkerPerformance.idl

Happily, usage is very low:
https://www.chromestatus.com/metrics/feature/timeline/popularity/885

Ah, my bad confused interfaces.. 

- Removing SharedWorker#workerStart sgtm.
- We should update the note in [1].. translateTime() was removed [2] and replaced with timeOrigin [3]

[1] https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/timing/SharedWorkerPerformance.idl
[2] https://github.com/w3c/hr-time/pull/31
[3] https://github.com/w3c/hr-time/commit/6d4edaaee9bffead39ca96d84db6128e878147bb

Updating title to "remove SharedWorker#workerStart". For context, workerStart was deprecated in [1], and was replaced with performance.timeOrigin which we're tracking in [2]. 


[1] https://github.com/w3c/hr-time/commit/39aaf81e1ea206fdf0fde4f49604ddd64d4f5b13
[2]  crbug.com/739277 

Intent to remove thread, with 3 lgtms: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/KkPl_Szxf50

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b8d86d2709522258e3efa092da2edcaa6f3a63c0

commit b8d86d2709522258e3efa092da2edcaa6f3a63c0
Author: Nicolas Pena <npm@chromium.org>
Date: Thu Jul 27 17:13:15 2017

Remove SharedWorkerPerformance idl

Intent to Deprecate and Remove:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/KkPl_Szxf50

Bug:  chromium:695996 
Change-Id: I37ce8f1a7275fc66e12af0f3f708a42bc1a97735
Reviewed-on: https://chromium-review.googlesource.com/563856
Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Rick Byers <rbyers@chromium.org>
Reviewed-by: Timothy Dresser <tdresser@chromium.org>
Commit-Queue: Nicolás Peña <npm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#489997}
[modify] https://crrev.com/b8d86d2709522258e3efa092da2edcaa6f3a63c0/third_party/WebKit/LayoutTests/http/tests/w3c/webperf/submission/Google/HighResolutionTime/worker-shared-basic.html
[modify] https://crrev.com/b8d86d2709522258e3efa092da2edcaa6f3a63c0/third_party/WebKit/LayoutTests/platform/mac/virtual/stable/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/b8d86d2709522258e3efa092da2edcaa6f3a63c0/third_party/WebKit/LayoutTests/platform/win/virtual/stable/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/b8d86d2709522258e3efa092da2edcaa6f3a63c0/third_party/WebKit/LayoutTests/virtual/service-worker-navigation-preload-disabled/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/b8d86d2709522258e3efa092da2edcaa6f3a63c0/third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/b8d86d2709522258e3efa092da2edcaa6f3a63c0/third_party/WebKit/Source/core/core_idl_files.gni
[modify] https://crrev.com/b8d86d2709522258e3efa092da2edcaa6f3a63c0/third_party/WebKit/Source/core/timing/BUILD.gn
[delete] https://crrev.com/700d01a85c01dafab99da154d7480eac1a0d2bf0/third_party/WebKit/Source/core/timing/SharedWorkerPerformance.cpp
[delete] https://crrev.com/700d01a85c01dafab99da154d7480eac1a0d2bf0/third_party/WebKit/Source/core/timing/SharedWorkerPerformance.h
[delete] https://crrev.com/700d01a85c01dafab99da154d7480eac1a0d2bf0/third_party/WebKit/Source/core/timing/SharedWorkerPerformance.idl
[modify] https://crrev.com/b8d86d2709522258e3efa092da2edcaa6f3a63c0/tools/blink_rename_merge_helper/data/idl_blocklist.txt