Only remaining deployed uses are in core. Some already have patches pending from related fixes to the same code.
`getContentHandler`:
[] RevisionDbTest
[] `SpecialUndelete::showDiff` - https://gerrit.wikimedia.org/r/c/591524
[] `SpecialComparePages::showDiff` (also uses `Revision::newFromId`)
[x] `WikiPage::getUndoContent` (method is hard deprecated)
[] `Article::showDiffPage`
[] `RollbackAction::handleRollbackRequest` - https://gerrit.wikimedia.org/r/c/592318
[] `FeedUtils::formatDiffRow` (also uses `Revision::newFromId`)
`getContentModel`
[] RevisionTest
[] RevisionDbTest
[] RevisionStoreDbTestBase
[] EditPage - https://gerrit.wikimedia.org/r/c/587904
`getContentFormat`
[] `ResourceLoaderWikiModule::invalidateModuleCache` - https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/587571/
[] RevisionStoreDbTestBase
[] RevisionDbTest