unable to highlight sync words for copying

[LaurenWags]

Test plan

#11670 (comment)

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Description

On the 'Sync a new device' popup we are no longer able to highlight the sync words so we can copy/paste them. This last worked with 0.19.54 and stopped working in 0.19.57.

Steps to Reproduce

1. Enable sync.
2. Open 'Sync a new device' popup.
3. Select 'show secret code words'.

Actual result:
Unable to highlight the sync code words:

Expected result:
Should be able to highlight the sync code words as before.

Reproduces how often: [What percentage of the time does it reproduce?] 100%

Brave Version

about:brave info:
Brave | 0.19.62
rev | fe3f350
Muon | 4.5.7

Reproducible on current live release:
no, this is not broken on 0.19.53

Additional Information

Possibly introduced with cr62, which was also introduced in 0.19.57.
cc @srirambv

[luixxiul]

https://github.com/brave/browser-laptop/blame/1bb8ff174e8781db05d48c0c86de41e19d04e048/app/renderer/components/preferences/syncTab.js#L608

user-select: initial seems to have changed how it behaves since cr62 (since the code has been there for 6 month). there might be a similar case inside the code.

changing it to user-select: text should work.

[luixxiul]

Since the fix is ready (PR has been submitted), it is ok to escalate this to hotfix 2.

[bsclifton]

This will be an important one to test on Windows (which is a little more picky about these attributes)

[kjozwiak]

This issue also affected the backup keys under about:preferences#payments, checked on all the platforms to ensure that it has been resolved with this fix as well:

• Ubuntu 17.04 x64 - Copied both sync & wallet keys using the cursor without any issues
• macOS x64 - Copied wallet keys using the cursor without any issues (sync already checked)
• Win 10 x64 - Copied wallet keys using the cursor without any issues (sync already checked)