+++ This bug was initially created as a clone of Bug #584551 +++ XPCJSContextStack::Push is often followed by JS_BeginRequest/JSAutoREquest. This is suboptimal because Push may also call JS_SuspendRequest on the previous context meaning that the GC lock is taken twice. With changes from bug 552266 we can skip JS_SuspendRequest and call only JS_BeginRequest as the latter automatically suspends the previous active context. Thus the idea is to have a form of Push that would also enter the request.