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..7aa4cfdc2714b9458dd958e902b43fa9f8facdd7 100644
--- a/chrome/renderer/resources/extensions/event.js
+++ b/chrome/renderer/resources/extensions/event.js
@@ -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.mDnsServiceTypes &&
+          !(filters.mDnsSerivceTypes instanceof Array)) {
+        throw new Error("filters.mDnsServiceTypes should be an array.")
+      }
     }
     var listener = {callback: cb, filters: filters};
     this.attach_(listener);