RealtimeWYSIWYGEditorIT#editFullScreen is flickering

I managed to reproduce with Chrome in the end. The test was returning from in-place edit to view mode after solving a merge conflict. The test was waiting for the merged conflicts to be solved, i.e. for the Saved message, but not for the view mode to be ready. Going from in-place edit to view mode happens without a page reload, and XWiki.editor remains set until view mode is ready. Without a wait for view mode to be ready TestUtils#maybeLeaveEditMode was seeing XWiki.editor set so it thought it was still in edit mode and waited for the Cancel button to be enabled. But since we were going to view mode the Cancel button remained disabled (it's still present after ending in-place edit, to be used for the next in-place edit session).