Bug 1348416 - Update pdf.js to version 1.7.367: Use shiny new complex string pref getter and setter. r=eslint-fix

browser/extensions/pdfjs/content/PdfStreamConverter.jsm

@@ -93,7 +93,7 @@ function getIntPref(pref, def) {
 
 function getStringPref(pref, def) {
   try {
-    return Services.prefs.getComplexValue(pref, Ci.nsISupportsString).data;
+    return Services.prefs.getStringPref(pref);
   } catch (ex) {
     return def;
   }

browser/extensions/pdfjs/content/PdfjsChromeUtils.jsm

@@ -290,10 +290,7 @@ var PdfjsChromeUtils = {
 
   _setStringPref(aPrefName, aPrefValue) {
     this._ensurePreferenceAllowed(aPrefName);
-    let str = Cc["@mozilla.org/supports-string;1"]
-                .createInstance(Ci.nsISupportsString);
-    str.data = aPrefValue;
-    Services.prefs.setComplexValue(aPrefName, Ci.nsISupportsString, str);
+    Services.prefs.setStringPref(aPrefName, aPrefValue);
   },
 
   /*