Chrome Version       : 1.0.154.36
URLs (if applicable) :
Other browsers tested:
Add OK or FAIL after other browsers where you have tested this issue:
     Safari 3: Unknown
    Firefox 3: OK
         IE 7: OK (using COM instead of npruntime)

What steps will reproduce the problem?
1. In an npruntime plugin, create an NPObject implementing the enumerate
callback. The callback should return an array of ids of properties
contained in the object.
2. From JavaScript, use the for-in loop to enumerate the properties:

var obj = plugin.createObject();
for (var p in obj) {
  alert(p);
}

What is the expected result?
The NPObject's enumerate callback should be called. All ids returned by the
callback should reported as values of 'p' in the for-in loop.

What happens instead?
The enumerate callback is not called.

Please provide any additional information below. Attach a screenshot if
possible.

I tracked this problem down to CreateV8ObjectForNPObject in
webkit/port/bindings/v8/v8_npobject.cpp. The function creates a V8 proxy to
wrap the NPObject. However, it does not register either indexed or named
property enumerators. CreateV8ObjectForNPObject should register property
enumerators that forward to the wrapped NPObject's enumerate callback function.