Debugging for https://crbug.com/601435.

mojo/public/js/connector.js

Index: mojo/public/js/connector.js
diff --git a/mojo/public/js/connector.js b/mojo/public/js/connector.js
index 674f36b3210d3fced0abd04c1163fcfac49933b9..9b9061943943950c3dc96480c4e60d1723aa27b2 100644
--- a/mojo/public/js/connector.js
+++ b/mojo/public/js/connector.js
@@ -9,6 +9,9 @@ define("mojo/public/js/connector", [
   "mojo/public/js/support",
 ], function(buffer, codec, core, support) {
 
+  // Putting the handles somewhere causes them to not get lost.
+  var allHandles = [];
+
   function Connector(handle) {
     if (!core.isHandle(handle))
       throw new Error("Connector: not a handle " + handle);
@@ -44,6 +47,7 @@ define("mojo/public/js/connector", [
     if (this.dropWrites_)
       return true;
 
+    allHandles = allHandles.concat(message.handles);
     var result = core.writeMessage(this.handle_,
                                    new Uint8Array(message.buffer.arrayBuffer),
                                    message.handles,