Initial chrome.mdns API.

chrome/renderer/resources/extensions/event.js

Index: chrome/renderer/resources/extensions/event.js
diff --git a/chrome/renderer/resources/extensions/event.js b/chrome/renderer/resources/extensions/event.js
index 13ad277481dc0391d4e8a3cb6ff8503cef33b67c..c6c5a0fc0151355d542192d2237caf3f213a3859 100644
--- a/chrome/renderer/resources/extensions/event.js
+++ b/chrome/renderer/resources/extensions/event.js
@@ -228,7 +228,7 @@
   // Dispatches a named event with the given argument array. The args array is
   // the list of arguments that will be sent to the event callback.
   function dispatchEvent(name, args, filteringInfo) {
-    var listenerIDs = null;
+    var listenerIDs = [];
 
     if (filteringInfo)
       listenerIDs = eventNatives.MatchAgainstEventFilter(name, filteringInfo);
@@ -262,7 +262,11 @@
       if (!this.eventOptions_.supportsFilters)
         throw new Error("This event does not support filters.");
       if (filters.url && !(filters.url instanceof Array))
-        throw new Error("filters.url should be an array");
+        throw new Error("filters.url should be an array.");
+      if (filters.serviceType &&
+          !(typeof filters.serviceType === 'string')) {
+        throw new Error("filters.serviceType should be a string.")
+      }
     }
     var listener = {callback: cb, filters: filters};
     this.attach_(listener);