Why is the behavior different between Chrome and IE11 when making two window.location.href assignments in a row?
Chrome ignores the first assignment and will only issue a request for the last one.
IE11 will send a request for the both.
Repro'd here.
NOTE: You'll need to use a tool that can track the outbound requests like fiddler or similar to see the request go out on IE11.
It's up to the browser how to implement things like setting the location. One browser probably begins tearing down immediately, and the other probably continues running JavaScript until it's time for the next page to load. In Chrome, it is probably making both requests but the first is cancelled so quickly that it never actually makes it out of the browser.