My C++ is really rusty, and I'm reading the diff out of context, but I believe that this patch just lets you add URLs to two lists, one that gets POSTs for every new block that comes in, and one that gets POSTs for every transaction that comes in related to the running wallet.
I hope this is not the case, and it doesn't make sense. If you're receiving blocks complete with all transactions and you have addresses in your POST queue for monitortx why would you go out of your way to filter results based on the wallet? It's an extra step to reduce functionality.