Get and update sync code only after sync chain is created

[darkdh]

Otherwise, we end up caching wrong sync code when page is loaded and it
will only be updated after a page refresh

Resolves brave/brave-browser#10857

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Verified that these changes build without errors on
  • Android
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that these changes pass automated tests (unit, browser, security tests) on
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that all lint errors/warnings are resolved (npm run lint)
• Ran git rebase master (if needed).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed.
• Add appropriate QA labels (QA/Yes or QA/No) to include the closed issue in milestone
• Public documentation has been updated as necessary. For instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-compatibility-issues-with-tracking-protection
  • https://github.com/brave/brave-browser/wiki/QA-Guide

Test Plan:

1. STR in [Desktop] Wrong code words are shown in View Sync Code after sync creation brave-browser#10857
2. Reset sync chain
3. Create a new sync chain and remember the sync code
4. After sync chain created, click View Sync Code
5. Code in step 3 & 4 should be the same

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on.
• All relevant documentation has been updated.

[darkdh]

restart CI for window only

[petemill]

Just 1 minor issue

[petemill]

My preference would be to call this ensureSetSyncCode or at least not have get in it, since it's confusing when reading the calls to it as getXYZ implies returning a value.

[darkdh]

fixed

[petemill]

@darkdh was this issue caused because the 'configure' component is not removed and re-attached when finishing setting up the new sync chain and exiting the sync section?
If there's still a timing issue with this fix in the future, the proper fix is probably to have the syncCode bubble down from the main sync page component.

[darkdh]

@darkdh was this issue caused because the 'configure' component is not removed and re-attached when finishing setting up the new sync chain and exiting the sync section?
If there's still a timing issue with this fix in the future, the proper fix is probably to have the syncCode bubble down from the main sync page component.

No, it is actually caused by user navigate to sync page for the first time without any sync chain setup. At that point, it tries to get sync code from pref but it shouldn't

[bsclifton]

Works perfectly! 👍 Thanks for adding the comment and fixing the reset sync chain case 😄

[petemill]

LGTM

[btlechowski]

LGTM

Verification passed on

Brave	1.13.50 Chromium: 84.0.4147.105 (Official Build) nightly (64-bit)
Revision	a6b12dfad6663f13a7e16e9a42a6a4975374096b-refs/branch-heads/4147@{#943}
OS	Ubuntu 18.04 LTS

Verified test plan from #6182 (comment).
Verified test case from brave/brave-browser#10857 (comment)