Make isinstance() and template.highlight Symbol aware.

common/modules/base.jsm

@@ -646,7 +646,8 @@ var isinstance_types = {
     boolean: Boolean,
     string: String,
     function: Function,
-    number: Number
+    number: Number,
+    symbol: Symbol
 };
 function isinstance(object, interfaces) {
     if (object == null)

common/modules/template.jsm

@@ -284,10 +284,13 @@ var Template = Module("Template", {
                 if (processStrings)
                     str = JSON.stringify(str);
                 return ["span", { highlight: "String" }, str];
+            case "symbol":
+                return ["span", { highlight: "Symbol" }, str];
             case "boolean":
                 return ["span", { highlight: "Boolean" }, str];
             case "function":
-                if (arg instanceof Ci.nsIDOMElement) // wtf?
+                // See: https://bugzil.la/268945
+                if (arg instanceof Ci.nsIDOMElement)
                     return util.objectToString(arg, !bw);
 
                 str = str.replace("/* use strict */ \n", "/* use strict */ ");
@@ -310,8 +313,6 @@ var Template = Module("Template", {
                                                            { highlight: "NonText" },
                                                            "^J"]);
                 return ["span", { highlight: "Object" }, str];
-            case "xml":
-                return arg;
             default:
                 return "<unknown type>";
             }

common/skin/global-styles.css

@@ -4,6 +4,7 @@ Null         /* JavaScript null values */    color: blue;
 Number       /* JavaScript numbers */        color: blue;
 Object       /* JavaScript objects */        color: maroon;
 String       /* String values */             color: green; white-space: pre;
+Symbol       /* JavaScript symbols */        color: darkcyan;
 Comment      /* JavaScriptor CSS comments */ color: gray;
 
 Key          /* Keywords */                  font-weight: bold;