https://codereview.chromium.org/19541010/

The main problem is that if you called Object.getNotifier(obj) on an object, %SetObserved(object) would never get called on it, and thus it would be unobservable (new test added for this).

Additionally, Runtime::SetObserved was asserting obj->IsJSObject() which would fail if called on a proxy.

It just happens that our existing test always called getNotifier() before Object.observe on proxies, and thus we never previously attempted to transition the map of a proxy.

Both issues are now fixed and properly tested.

R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/21891008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16074 ce2b1a6d-e550-0410-aec6-3dcde31c8c00