sometimes attach/detach of tab causes crash

[LaurenWags]

Description

Sometimes attaching or detaching a tab causes Brave to crash.

Steps to Reproduce

1. Launch Brave with a clean profile using 0.22.103
2. Open a site with links such as wikipedia.org
3. I used middle click on a few links to open some tabs
4. Click on one of the tabs to make it the active tab and drag it away from the window.

Actual result:
Sometimes Brave crashes, but not always. I also found that if it doesn't crash at this point, if you reattach and detach a couple of times that usually causes the crash as well.

Crash Report ID: d8fe8367af726838

terminal output: https://gist.github.com/LaurenWags/08605195bfe723409b4de397452489fc#file-crash-detach-reattach-txt

Expected result:
Should not crash

Reproduces how often:
unsure

Brave Version

about:brave info:
Brave | 0.22.103
V8 | 6.5.254.41
rev | 2324f55
Muon | 6.0.0
OS Release | 16.7.0
Update Channel | Beta
OS Architecture | x64
OS Platform | macOS
Node.js | 7.9.0
Brave Sync | v1.4.2
libchromiumcontent | 65.0.3325.181

Reproducible on current live release:
no

Additional Information

[LaurenWags]

Experienced a crash when reattaching tabs to the original window - crashID: 12850224dc5bca5a

[petemill]

This could be the "pending response" crash that @bridiver is looking in to

[bridiver]

this is likely fixed in 6.0.3

[LaurenWags]

Verified with macOS 10.12.6 using

• 0.22.702 e4a853d
• muon 6.0.7
• libchromiumcontent 66.0.3359.139

Verified on Windows x64

• 0.22.702 e4a853d
• libchromiumcontent 66.0.3359.139
• muon: 6.0.7

Verified on Ubuntu 17.10 x64

• 0.22.703 903b8d0
• libchromiumcontent 66.0.3359.139
• muon: 6.0.8