merge_pr_49022

Always preserve collapsible spaces in text controls.

Differential Revision: https://phabricator.services.mozilla.com/D228129

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1905904
gecko-commit: 53711e5bca1a324c5ca26bddc9a0d58920259942
gecko-reviewers: masayuki