chrome.contextMenus.remove && chrome.contextMenus.update

[dividinglimits]

supports: #8789 and #8332
updates: #8331

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
  Already exists
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).
  Not necessary
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed. (Ask a Brave employee to help if you cannot access this document.)

Test Plan:

Reviewer Checklist:

• Request a security/privacy review as needed if one was not already requested.

Tests

• Adequate test coverage exists to prevent regressions
• Tests should be independent and work correctly when run individually or as a suite ref
• New files have MPL2 license header

[codecov-io]

Codecov Report

Merging #12659 into master will decrease coverage by 0.29%.
The diff coverage is 12.57%.

@@            Coverage Diff            @@
##           master   #12659     +/-   ##
=========================================
- Coverage   56.24%   55.94%   -0.3%     
=========================================
  Files         278      278             
  Lines       27115    27255    +140     
  Branches     4392     4414     +22     
=========================================
- Hits        15250    15248      -2     
- Misses      11865    12007    +142

Flag	Coverage Δ
#unittest	55.94% <12.57%> (-0.3%)	⬇️

Impacted Files	Coverage Δ
app/common/constants/extensionConstants.js	100% <ø> (ø)	⬆️
js/stores/appStore.js	16.11% <0%> (-0.1%)	⬇️
app/common/actions/extensionActions.js	24.13% <0%> (-3.87%)	⬇️
app/common/state/extensionState.js	35.23% <13.12%> (-25.7%)	⬇️
app/common/state/aboutNewTabState.js	94.87% <0%> (-5.13%)	⬇️
js/about/newtab.js	40.95% <0%> (-2.06%)	⬇️
app/common/state/pinnedSitesState.js	77.98% <0%> (-1.07%)	⬇️
app/browser/api/topSites.js	94.28% <0%> (-0.26%)	⬇️
app/sessionStore.js	88.79% <0%> (+0.04%)	⬆️
... and 2 more

[kevinlawler]

this is a nice-looking changeset
I don't see any obvious red flags, but I am not an expert on the tab state, so can't comment on the soundness of the logic

[bsclifton]

@jonathansampson did you want to give this a review? I know it's a bit old, but we could still merge this patch