function _getFunctionsInFiles(fileInfos) {
        var result      = new $.Deferred(),
            docEntries  = [];

        PerfUtils.markStart(PerfUtils.JSUTILS_GET_ALL_FUNCTIONS);

        Async.doInParallel(fileInfos, function (fileInfo) {
            var oneResult = new $.Deferred();

            _getFunctionsForFile(fileInfo)
                .done(function (docInfo) {
                    docEntries.push(docInfo);
                })
                .always(function (error) {
                    // If one file fails, continue to search
                    oneResult.resolve();
                });

            return oneResult.promise();
        }).always(function () {
            // Reset ChangedDocumentTracker now that the cache is up to date.
            _changedDocumentTracker.reset();

            PerfUtils.addMeasurement(PerfUtils.JSUTILS_GET_ALL_FUNCTIONS);
            result.resolve(docEntries);
        });

        return result.promise();
    }
@private
Get all functions for each FileInfo.
@param {Array.<FileInfo>} fileInfos
@return {$.Promise} A promise resolved with an array of document info objects that each
  contain a map of all function names from the document and each function's start offset.