function isCSSPreprocessorFile(filePath) {
        var languageId = LanguageManager.getLanguageForPath(filePath).getId();
        return (languageId === "less" || languageId === "scss");
    }
Determines if the given path is a CSS preprocessor file that CSSUtils supports.
@param {string} filePath Absolute path to the file.
@return {boolean} true if LanguageManager identifies filePath as less or scss language.