Bisected to 2943ded4713e9dffff514843c61467f41140b282 = https://crrev.com/c/940774 by luoe@chromium.org
"DevTools: add frontend support for BigInt"
Landed in 67.0.3367.0

The CL adds unserializableValue() to objects which leads to the wrong if-branch being executed in toCallArgument:
https://cs.chromium.org/chromium/src/third_party/blink/renderer/devtools/front_end/sdk/RemoteObject.js?l=115&rcl=7ebede76882fac9b113e5e272dbada9f5da423fd

Repro:
1. run chrome with the following command line parameters:
   --remote-debugging-port=9222 http://localhost:9222 about:blank
2. open devtools
3. click "about:blank" item in the page
4. in the outer devtools (opened in step 2) switch to Network panel
5. click the item that consists of many capslock letters and digits
6. click "Frames"
7. click any item in this list
8. below the list rightclick the first row, click "Store as global variable"
9. observe the console

Expected: the actual value is shown
Observed: "undefined" is shown

Deleted: good.png 93.5 KB

	good.png 93.5 KB View Download

Deleted: bad.png 81.3 KB

	bad.png 81.3 KB View Download

*** Bulk Edit ***
M67 Stable promotion is coming VERY soon. Your bug is labelled as Stable ReleaseBlock, pls make sure to land the fix and request a merge into the release branch ASAP. 

If fix is already merged to M67 and nothing else is pending, pls mark the bug as fixed. Thank you.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c304c47ca16e77c6a39bc428600d2cf8249f9f90

commit c304c47ca16e77c6a39bc428600d2cf8249f9f90
Author: Erik Luo <luoe@chromium.org>
Date: Tue May 08 00:40:41 2018

DevTools: properly call unserializableValue for LocalJSONObject

'Store as global variable' path for LocalJSONObject (e.g. JSONView)
was not tested, and broke because:
- LocalJSONObject did not override unserializableValue()
- ToCallArgument returned instead of invoking unserializableValue()

Bug:  840313 
Change-Id: I19c7e5eda2d788fdbba397e00af2eecfab7b2888
Reviewed-on: https://chromium-review.googlesource.com/1048105
Commit-Queue: Erik Luo <luoe@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556625}
[add] https://crrev.com/c304c47ca16e77c6a39bc428600d2cf8249f9f90/third_party/WebKit/LayoutTests/http/tests/devtools/unit/remote-object-from-local-expected.txt
[add] https://crrev.com/c304c47ca16e77c6a39bc428600d2cf8249f9f90/third_party/WebKit/LayoutTests/http/tests/devtools/unit/remote-object-from-local.js
[modify] https://crrev.com/c304c47ca16e77c6a39bc428600d2cf8249f9f90/third_party/blink/renderer/devtools/front_end/sdk/RemoteObject.js
[modify] https://crrev.com/c304c47ca16e77c6a39bc428600d2cf8249f9f90/third_party/blink/renderer/devtools/front_end/sdk/RuntimeModel.js

This is working again in latest Canary. Thanks!

luoe@ can you please merge-request the CL from Comment#4 into M67 branch.

Thanks for the reminder, requesting here.

This bug requires manual review: M67 has already been promoted to the beta branch, so this requires manual review
Please contact the milestone owner if you have questions.
Owners: cmasso@(Android), cmasso@(iOS), kbleicher@(ChromeOS), govind@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Approving merge to M67 branch 3396 based on comment #5 & per offline chat with luoe@. Please merge ASAP. Also mark the bug as fixed if nothing else is pending after the merge. Thank you.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/724ebeffb6c398a3029467ec2f1f99a8f5d0c893

commit 724ebeffb6c398a3029467ec2f1f99a8f5d0c893
Author: Erik Luo <luoe@chromium.org>
Date: Wed May 09 22:24:54 2018

DevTools: properly call unserializableValue for LocalJSONObject

'Store as global variable' path for LocalJSONObject (e.g. JSONView)
was not tested, and broke because:
- LocalJSONObject did not override unserializableValue()
- ToCallArgument returned instead of invoking unserializableValue()

Bug:  840313 
Change-Id: I19c7e5eda2d788fdbba397e00af2eecfab7b2888
Reviewed-on: https://chromium-review.googlesource.com/1048105
Commit-Queue: Erik Luo <luoe@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#556625}(cherry picked from commit c304c47ca16e77c6a39bc428600d2cf8249f9f90)
Reviewed-on: https://chromium-review.googlesource.com/1053247
Reviewed-by: Erik Luo <luoe@chromium.org>
Cr-Commit-Position: refs/branch-heads/3396@{#539}
Cr-Branched-From: 9ef2aa869bc7bc0c089e255d698cca6e47d6b038-refs/heads/master@{#550428}
[add] https://crrev.com/724ebeffb6c398a3029467ec2f1f99a8f5d0c893/third_party/WebKit/LayoutTests/http/tests/devtools/unit/remote-object-from-local-expected.txt
[add] https://crrev.com/724ebeffb6c398a3029467ec2f1f99a8f5d0c893/third_party/WebKit/LayoutTests/http/tests/devtools/unit/remote-object-from-local.js
[modify] https://crrev.com/724ebeffb6c398a3029467ec2f1f99a8f5d0c893/third_party/blink/renderer/devtools/front_end/sdk/RemoteObject.js
[modify] https://crrev.com/724ebeffb6c398a3029467ec2f1f99a8f5d0c893/third_party/blink/renderer/devtools/front_end/sdk/RuntimeModel.js