Function watchFile

test/fixtures/snapshot/typescript.js:6259–6276

(fileName, callback, defaultPollingInterval)

        var highPollingIntervalQueue = createPollingIntervalQueue(PollingInterval.High);
        return watchFile;
        function watchFile(fileName, callback, defaultPollingInterval) {
            var file = {
                fileName: fileName,
                callback: callback,
                unchangedPolls: 0,
                mtime: getModifiedTime(host, fileName)
            };
            watchedFiles.push(file);
            addToPollingIntervalQueue(file, defaultPollingInterval);
            return {
                close: function () {
                    file.isClosed = true;
                    // Remove from watchedFiles
                    ts.unorderedRemoveItem(watchedFiles, file);
                    // Do not update polling interval queue since that will happen as part of polling
                }
            };
        }
        function createPollingIntervalQueue(pollingInterval) {
            var queue = [];
            queue.pollingInterval = pollingInterval;