With the recent change to adopt asType() style cast functions with assertions instead of static_casts in many places, the assertion for the asObject() call in JSCallbackObject::getOwnPropertySlot() has been failing when using any nontrivial client of the JavaScriptCore API. The cast isn't even necessary to call slot.setCustom(), so it should be removed.
Created attachment 25011 [details] Proposed patch
Comment on attachment 25011 [details] Proposed patch r=me
Landed in r38265.