Comment 42 for bug 1811105

I'm seeing some strange results in https://perfht.ml/2W2Uejq. There's a call to nsViewManager::DispatchEvent, followed by about a billion calls to std::deque::_M_reallocate_map, followed by calls to LifecycleGetCustomInterfaceCallback (the thing that got replaced with a C++ call in Bug 1492326). I wonder if we are still having the calls to std::deque::_M_reallocate_map but the C++ Qi is just a lot faster, so it isn't noticeable.