475768e076
The xulRuntime object needs to be created inside the sandbox, or code running inside the sandbox will hit some kind of wrapper when attempting to access it, causing thousands of warnings when evaluating the test conditions: Silently denied access to property "shell": Access to privileged JS object not permitted Differential Revision: https://phabricator.services.mozilla.com/D257186
Reftest documentation has been moved to layout/docs/Reftest.rst and is rendered at https://firefox-source-docs.mozilla.org/layout/Reftest.html