It's not clear to me what NOTIFY_IME_OF_COMPOSITION_UPDATE means only from the name. For making the name clearer, this patch renames it to NOTIFY_IME_OF_COMPOSITION_EVENT_HANDLED and add some explanation to the definition.
MozReview-Commit-ID: 8ySYCNJ1Ytz
--HG--
extra : rebase_source : 3331b8f48e8b460c7f9b088064dcda9488f3403c