function _onDirtyFlagChange(event, doc) {
        if (!isActive() || !_server) {
            return;
        }

        var absolutePath = doc.file.fullPath;

        if (_liveDocument.isRelated(absolutePath)) {
            // Set status to out of sync if dirty. Otherwise, set it to active status.
            _setStatus(_docIsOutOfSync(doc) ? STATUS_OUT_OF_SYNC : STATUS_ACTIVE);
        }
    }
For files that don't support as-you-type live editing, but are loaded by live HTML documents
(e.g. JS files), we want to show a dirty indicator on the live development icon when they
have unsaved changes, so the user knows s/he needs to save in order to have the page reload.
@param {$.Event} event
@param {Document} doc