A request observer proxy is used to ship data over to another thread specified
 by the thread's event queue. The "true" request observer's methods are 
 invoked on the other thread.

 This interface only provides the initialization needed after construction. Otherwise,
 these objects are used simply as nsIRequestObserver's.
[scriptable, uuid(3c9b532e-db84-4ecf-aa6a-4d38a9c4c5f0)]
interface nsIRequestObserverProxy : nsIRequestObserver

Methods

 Initializes an nsIRequestObserverProxy.

 @param observer - receives observer notifications on the other thread
 @param eventQ - may be NULL indicating the calling thread's event queue
void init(in nsIRequestObserver observer, in nsIEventQueue eventQ)