function _toggleProjectScope() {
        if (_includeProjectScope() === projectScopeIsIncluded) {
            return;
        }
        if (projectScopeIsIncluded) {
            PreferencesImpl.manager.removeFromScopeOrder("project");
        } else {
            PreferencesImpl.manager.addToScopeOrder("project", "user");
        }
        projectScopeIsIncluded = !projectScopeIsIncluded;
    }
@private

Adds or removes the project Scope as needed based on whether the currently
edited file is within the project.