--- a/security/manager/tools/getHSTSPreloadList.js
+++ b/security/manager/tools/getHSTSPreloadList.js
@@ -12,16 +12,19 @@
 // Note: Running this file outputs a new nsSTSPreloadlist.inc in the current
 //       working directory.
 
 var Cc = Components.classes;
 var Ci = Components.interfaces;
 var Cu = Components.utils;
 var Cr = Components.results;
 
+var gSSService = Cc["@mozilla.org/ssservice;1"]
+                   .getService(Ci.nsISiteSecurityService);
+
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/FileUtils.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
 const SOURCE = "https://chromium.googlesource.com/chromium/src/net/+/master/http/transport_security_state_static.json?format=TEXT";
 const OUTPUT = "nsSTSPreloadList.inc";
 const ERROR_OUTPUT = "nsSTSPreloadList.errors";
 const MINIMUM_REQUIRED_MAX_AGE = 60 * 60 * 24 * 7 * 18;
@@ -40,51 +43,51 @@ const HEADER = "/* This Source Code Form
 "/* This is an automatically generated file. If you're not                    */\n" +
 "/* nsSiteSecurityService.cpp, you shouldn't be #including it.     */\n" +
 "/*****************************************************************************/\n" +
 "\n" +
 "#include <stdint.h>\n";
 const GPERF_DELIM = "%%\n";
 
 function download() {
-  var req = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
+  let req = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
             .createInstance(Ci.nsIXMLHttpRequest);
   req.open("GET", SOURCE, false); // doing the request synchronously
   try {
     req.send();
   } catch (e) {
     throw new Error(`ERROR: problem downloading '${SOURCE}': ${e}`);
   }
 
   if (req.status != 200) {
     throw new Error("ERROR: problem downloading '" + SOURCE + "': status " +
                     req.status);
   }
 
-  var resultDecoded;
+  let resultDecoded;
   try {
     resultDecoded = atob(req.responseText);
   } catch (e) {
     throw new Error("ERROR: could not decode data as base64 from '" + SOURCE +
                     "': " + e);
   }
 
   // we have to filter out '//' comments, while not mangling the json
-  var result = resultDecoded.replace(/^(\s*)?\/\/[^\n]*\n/mg, "");
-  var data = null;
+  let result = resultDecoded.replace(/^(\s*)?\/\/[^\n]*\n/mg, "");
+  let data = null;
   try {
     data = JSON.parse(result);
   } catch (e) {
     throw new Error(`ERROR: could not parse data from '${SOURCE}': ${e}`);
   }
   return data;
 }
 
 function getHosts(rawdata) {
-  var hosts = [];
+  let hosts = [];
 
   if (!rawdata || !rawdata.entries) {
     throw new Error("ERROR: source data not formatted correctly: 'entries' " +
                     "not found");
   }
 
   for (let entry of rawdata.entries) {
     if (entry.mode && entry.mode == "force-https") {
@@ -100,27 +103,24 @@ function getHosts(rawdata) {
         throw new Error("ERROR: entry not formatted correctly: no name found");
       }
     }
   }
 
   return hosts;
 }
 
-var gSSService = Cc["@mozilla.org/ssservice;1"]
-                   .getService(Ci.nsISiteSecurityService);
-
 function processStsHeader(host, header, status, securityInfo) {
-  var maxAge = { value: 0 };
-  var includeSubdomains = { value: false };
-  var error = ERROR_NONE;
+  let maxAge = { value: 0 };
+  let includeSubdomains = { value: false };
+  let error = ERROR_NONE;
   if (header != null && securityInfo != null) {
     try {
-      var uri = Services.io.newURI("https://" + host.name);
-      var sslStatus = securityInfo.QueryInterface(Ci.nsISSLStatusProvider)
+      let uri = Services.io.newURI("https://" + host.name);
+      let sslStatus = securityInfo.QueryInterface(Ci.nsISSLStatusProvider)
                                   .SSLStatus;
       gSSService.processHeader(Ci.nsISiteSecurityService.HEADER_HSTS,
                                uri, header, sslStatus, 0,
                                Ci.nsISiteSecurityService.SOURCE_PRELOAD_LIST,
                                {}, maxAge, includeSubdomains);
     } catch (e) {
       dump("ERROR: could not process header '" + header + "' from " +
            host.name + ": " + e + "\n");
@@ -166,20 +166,20 @@ RedirectAndAuthStopper.prototype = {
     return this.QueryInterface(iid);
   },
 
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIChannelEventSink,
                                          Ci.nsIAuthPrompt2])
 };
 
 function getHSTSStatus(host, resultList) {
-  var req = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
+  let req = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
             .createInstance(Ci.nsIXMLHttpRequest);
-  var inResultList = false;
-  var uri = "https://" + host.name + "/";
+  let inResultList = false;
+  let uri = "https://" + host.name + "/";
   req.open("GET", uri, true);
   req.setRequestHeader("X-Automated-Tool",
                        "https://hg.mozilla.org/mozilla-central/file/tip/security/manager/tools/getHSTSPreloadList.js");
   req.timeout = REQUEST_TIMEOUT;
 
   let errorhandler = (evt) => {
     dump(`ERROR: error making request to ${host.name} (type=${evt.type})\n`);
     if (!inResultList) {
@@ -222,36 +222,36 @@ function compareHSTSStatus(a, b) {
 function writeTo(string, fos) {
   fos.write(string, string.length);
 }
 
 // Determines and returns a string representing a declaration of when this
 // preload list should no longer be used.
 // This is the current time plus MINIMUM_REQUIRED_MAX_AGE.
 function getExpirationTimeString() {
-  var now = new Date();
-  var nowMillis = now.getTime();
+  let now = new Date();
+  let nowMillis = now.getTime();
   // MINIMUM_REQUIRED_MAX_AGE is in seconds, so convert to milliseconds
-  var expirationMillis = nowMillis + (MINIMUM_REQUIRED_MAX_AGE * 1000);
-  var expirationMicros = expirationMillis * 1000;
+  let expirationMillis = nowMillis + (MINIMUM_REQUIRED_MAX_AGE * 1000);
+  let expirationMicros = expirationMillis * 1000;
   return "const PRTime gPreloadListExpirationTime = INT64_C(" + expirationMicros + ");\n";
 }
 
 function errorToString(status) {
   return (status.error == ERROR_MAX_AGE_TOO_LOW
           ? status.error + status.maxAge
           : status.error);
 }
 
 function output(sortedStatuses, currentList) {
   try {
-    var file = FileUtils.getFile("CurWorkD", [OUTPUT]);
-    var errorFile = FileUtils.getFile("CurWorkD", [ERROR_OUTPUT]);
-    var fos = FileUtils.openSafeFileOutputStream(file);
-    var eos = FileUtils.openSafeFileOutputStream(errorFile);
+    let file = FileUtils.getFile("CurWorkD", [OUTPUT]);
+    let errorFile = FileUtils.getFile("CurWorkD", [ERROR_OUTPUT]);
+    let fos = FileUtils.openSafeFileOutputStream(file);
+    let eos = FileUtils.openSafeFileOutputStream(errorFile);
     writeTo(HEADER, fos);
     writeTo(getExpirationTimeString(), fos);
 
     for (let status of sortedStatuses) {
       // If we've encountered an error for this entry (other than the site not
       // sending an HSTS header), be safe and don't remove it from the list
       // (given that it was already on the list).
       if (!status.forceInclude &&