I am pretty sure this was not the default behaviour for Google Maps API for quite some time, but it must have changed in the meantime.
I modified Fiddle provided by google: https://developers.google.com/maps/documentation/javascript/infowindows
added 1000px "content" div on on top:
<div style="height: 1000px">CONTENT</div>
and added "auto" opening of infowindow to the script
google.maps.event.addListenerOnce(map, 'tilesloaded', function () {
infowindow.open(map, marker);
});
JS Fiddle:
https://jsfiddle.net/ym3c2e8u/
Problem:
If you comment out opening infowindow line, notice that the page will load and show you the top "CONTENT".
If the infowindow is being opened, the browser will automatically scroll down to centre on this element.
This is really frustrating and I would like to prevent this behaviour.