1 files changed, 18 insertions, 0 deletions
diff --git a/mojo/public/js/interface_types.js b/mojo/public/js/interface_types.js
index 01ea2d1..e8ed37a 100644
--- a/mojo/public/js/interface_types.js
+++ b/mojo/public/js/interface_types.js
@@ -6,6 +6,11 @@ define("mojo/public/js/interface_types", [
   "mojo/public/js/core",
 ], function(core) {
 
+  // Constants ----------------------------------------------------------------
+  var kInterfaceIdNamespaceMask = 0x80000000;
+  var kMasterInterfaceId = 0x00000000;
+  var kInvalidInterfaceId = 0xFFFFFFFF;
+
   // ---------------------------------------------------------------------------
 
   function InterfacePtrInfo(handle, version) {
@@ -44,9 +49,22 @@ define("mojo/public/js/interface_types", [
     this.handle = null;
   };
 
+  function isMasterInterfaceId(interfaceId) {
+    return interfaceId === kMasterInterfaceId;
+  }
+
+  function isValidInterfaceId(interfaceId) {
+    return interfaceId !== kInvalidInterfaceId;
+  }
+
   var exports = {};
   exports.InterfacePtrInfo = InterfacePtrInfo;
   exports.InterfaceRequest = InterfaceRequest;
+  exports.isMasterInterfaceId = isMasterInterfaceId;
+  exports.isValidInterfaceId = isValidInterfaceId;
+  exports.kInvalidInterfaceId = kInvalidInterfaceId;
+  exports.kMasterInterfaceId = kMasterInterfaceId;
+  exports.kInterfaceIdNamespaceMask = kInterfaceIdNamespaceMask;
 
   return exports;
 });