The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/136f3045f954f409b40e9d2523b25f113044b45f

commit 136f3045f954f409b40e9d2523b25f113044b45f
Author: Matt Falkenhagen <falken@chromium.org>
Date: Fri Jun 22 06:32:36 2018

Gardening: Enable WPT workers/semantics/structured-clone/{dedicated,shared}.html

Enables:
external/wpt/workers/semantics/structured-clone/dedicated.html
external/wpt/workers/semantics/structured-clone/shared.html

The upstream test changed and now these have stable failing results.

Bug:  855009 
Change-Id: I2f0c6a800668f58ad17eea1871af688fc5dfd781
TBR: tkent
Reviewed-on: https://chromium-review.googlesource.com/1111745
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569543}
[modify] https://crrev.com/136f3045f954f409b40e9d2523b25f113044b45f/third_party/WebKit/LayoutTests/TestExpectations
[add] https://crrev.com/136f3045f954f409b40e9d2523b25f113044b45f/third_party/WebKit/LayoutTests/external/wpt/workers/semantics/structured-clone/dedicated-expected.txt
[add] https://crrev.com/136f3045f954f409b40e9d2523b25f113044b45f/third_party/WebKit/LayoutTests/external/wpt/workers/semantics/structured-clone/shared-expected.txt

The test is now running! It fails for probably a silly reason:
FAIL RegExp new line assert_equals: source expected "\\n" but got "\n"
FAIL Array RegExp object, RegExp new line assert_equals: source expected "\\n" but got "\n"
FAIL Object RegExp object, RegExp new line assert_equals: source expected "\\n" but got "\n"

Adding to WorkerBacklog, anyone interested in taking? (I don't know exactly why this failure is happening).

Did some digging on this, I believe this is happening in v8 RegExp.

Running this line in the v8 shell returns false when it should return true:

     new RegExp('\n').source == '\\n'

Tested this on Firefox and it does return true. All other browsers are passing this test case and it is the only one that chrome is failing. (https://wpt.fyi/results/workers/semantics/structured-clone/dedicated.html?label=stable&aligned&q=workers%2Fsemantics%2Fstructured-clone%2Fdedicated.html)

This is a known issue since 2012, see v8:1982. Not sure what it will take to fix this but I can take a look.

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/0e22ec737bbfc76ee60cbe8b686e16f1f8e7aa48

commit 0e22ec737bbfc76ee60cbe8b686e16f1f8e7aa48
Author: Jakob Gruber <jgruber@chromium.org>
Date: Thu Dec 20 10:12:48 2018

[regexp] Escape newlines when setting [[OriginalSource]]

This escapes LineTerminator characters in a regexp pattern when
creating the string that will be stored in the [[OriginalSource]] slot.

As an example, the source property for all following objects will equal
"\n" (a '\' character followed by 'n'):

  /\n/
  new RegExp("\n")
  new RegExp("\\n")

Bug:  v8:1982 ,  chromium:855009 
Change-Id: I3b539497a0697e3d51ec969cae49308b0b312a19
Reviewed-on: https://chromium-review.googlesource.com/c/1384316
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58387}
[modify] https://crrev.com/0e22ec737bbfc76ee60cbe8b686e16f1f8e7aa48/src/objects.cc
[modify] https://crrev.com/0e22ec737bbfc76ee60cbe8b686e16f1f8e7aa48/test/mjsunit/regexp.js
[modify] https://crrev.com/0e22ec737bbfc76ee60cbe8b686e16f1f8e7aa48/test/test262/test262.status
[modify] https://crrev.com/0e22ec737bbfc76ee60cbe8b686e16f1f8e7aa48/test/webkit/fast/regex/toString-expected.txt

V8-side changes are done, passing back to falken@.

The NextAction date has arrived: 2018-12-20

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/cd5f5937cde8c2d2d0bf04c7735d4fa561338aa0

commit cd5f5937cde8c2d2d0bf04c7735d4fa561338aa0
Author: Michael Achenbach <machenbach@chromium.org>
Date: Thu Dec 20 12:48:43 2018

Revert "[regexp] Escape newlines when setting [[OriginalSource]]"

This reverts commit 0e22ec737bbfc76ee60cbe8b686e16f1f8e7aa48.

Reason for revert: Breaks layout tests:
https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8-Blink%20Linux%2064/28814

Original change's description:
> [regexp] Escape newlines when setting [[OriginalSource]]
> 
> This escapes LineTerminator characters in a regexp pattern when
> creating the string that will be stored in the [[OriginalSource]] slot.
> 
> As an example, the source property for all following objects will equal
> "\n" (a '\' character followed by 'n'):
> 
>   /\n/
>   new RegExp("\n")
>   new RegExp("\\n")
> 
> Bug:  v8:1982 ,  chromium:855009 
> Change-Id: I3b539497a0697e3d51ec969cae49308b0b312a19
> Reviewed-on: https://chromium-review.googlesource.com/c/1384316
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Mathias Bynens <mathias@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#58387}

TBR=yangguo@chromium.org,jgruber@chromium.org,mathias@chromium.org

Change-Id: I1db7e6a0c6cd1cd995fe9f499458108e88dc8cb9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  v8:1982 ,  chromium:855009 
Reviewed-on: https://chromium-review.googlesource.com/c/1386493
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58396}
[modify] https://crrev.com/cd5f5937cde8c2d2d0bf04c7735d4fa561338aa0/src/objects.cc
[modify] https://crrev.com/cd5f5937cde8c2d2d0bf04c7735d4fa561338aa0/test/mjsunit/regexp.js
[modify] https://crrev.com/cd5f5937cde8c2d2d0bf04c7735d4fa561338aa0/test/test262/test262.status
[modify] https://crrev.com/cd5f5937cde8c2d2d0bf04c7735d4fa561338aa0/test/webkit/fast/regex/toString-expected.txt

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8a922f2b87f1f99d0b7f72dcad011f08b75c927a

commit 8a922f2b87f1f99d0b7f72dcad011f08b75c927a
Author: Jakob Gruber <jgruber@chromium.org>
Date: Thu Dec 20 13:45:42 2018

Initiate rebaseline dance for V8 RegExp changes

Bug:  chromium:855009 
Change-Id: I169c0392c6caee8e14eaef734d7fd44f3ca0d2d0
Reviewed-on: https://chromium-review.googlesource.com/c/1386626
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#618201}
[modify] https://crrev.com/8a922f2b87f1f99d0b7f72dcad011f08b75c927a/third_party/blink/web_tests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fe6a58875e21eb3cd833b9507db2acabfb3f9834

commit fe6a58875e21eb3cd833b9507db2acabfb3f9834
Author: Fredrik Söderquist <fs@opera.com>
Date: Thu Dec 20 15:53:15 2018

Remove duplicate TestExpectations entries

TBR=verwaest@chromium.org,jgruber@chromium.org

Bug:  855009 , 916975
Change-Id: I1bf43a418707c064ca902f888161f91c278d91f0
Reviewed-on: https://chromium-review.googlesource.com/c/1386786
Reviewed-by: Fredrik Söderquist <fs@opera.com>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#618222}
[modify] https://crrev.com/fe6a58875e21eb3cd833b9507db2acabfb3f9834/third_party/blink/web_tests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/4edfaa1f39ef6c51b28dd0c6c39ed42bcb0c76fd

commit 4edfaa1f39ef6c51b28dd0c6c39ed42bcb0c76fd
Author: Jakob Gruber <jgruber@chromium.org>
Date: Fri Dec 21 09:15:09 2018

Reland "[regexp] Escape newlines when setting [[OriginalSource]]"

This is a reland of 0e22ec737bbfc76ee60cbe8b686e16f1f8e7aa48

Original change's description:
> [regexp] Escape newlines when setting [[OriginalSource]]
> 
> This escapes LineTerminator characters in a regexp pattern when
> creating the string that will be stored in the [[OriginalSource]] slot.
> 
> As an example, the source property for all following objects will equal
> "\n" (a '\' character followed by 'n'):
> 
>   /\n/
>   new RegExp("\n")
>   new RegExp("\\n")
> 
> Bug:  v8:1982 ,  chromium:855009 
> Change-Id: I3b539497a0697e3d51ec969cae49308b0b312a19
> Reviewed-on: https://chromium-review.googlesource.com/c/1384316
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Mathias Bynens <mathias@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#58387}

Bug:  v8:1982 ,  chromium:855009 
Change-Id: I1ba22395477ec37e8e8c944000f9beade1e3250b
Reviewed-on: https://chromium-review.googlesource.com/c/1386495
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58419}
[modify] https://crrev.com/4edfaa1f39ef6c51b28dd0c6c39ed42bcb0c76fd/src/objects.cc
[modify] https://crrev.com/4edfaa1f39ef6c51b28dd0c6c39ed42bcb0c76fd/test/mjsunit/regexp.js
[modify] https://crrev.com/4edfaa1f39ef6c51b28dd0c6c39ed42bcb0c76fd/test/test262/test262.status
[modify] https://crrev.com/4edfaa1f39ef6c51b28dd0c6c39ed42bcb0c76fd/test/webkit/fast/regex/toString-expected.txt

Rebaseline in flight: https://crrev.com/c/1397611

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c36c918c4372db8c29e1ed696bc2a9a60f09055f

commit c36c918c4372db8c29e1ed696bc2a9a60f09055f
Author: Jakob Gruber <jgruber@chromium.org>
Date: Mon Jan 07 12:29:51 2019

Rebaseline external/wpt/worked/semantics/structured-clone/ tests

Bug:  chromium:855009 
Change-Id: I16cb1baded307aea1bb1416084ffad036a4ffb6a
Reviewed-on: https://chromium-review.googlesource.com/c/1397611
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620296}
[modify] https://crrev.com/c36c918c4372db8c29e1ed696bc2a9a60f09055f/third_party/blink/web_tests/TestExpectations
[delete] https://crrev.com/3803455a8f665aa8e5e84a094cdfba6e7aa3547e/third_party/blink/web_tests/external/wpt/workers/semantics/structured-clone/dedicated-expected.txt
[delete] https://crrev.com/3803455a8f665aa8e5e84a094cdfba6e7aa3547e/third_party/blink/web_tests/external/wpt/workers/semantics/structured-clone/shared-expected.txt

Nice!