Chrome Version       : 62.0.3202.94
OS Version: Android

This is the Chrome equivalent of Firefox's https://bugzilla.mozilla.org/show_bug.cgi?id=1423017. Some context in:

https://github.com/bokand/bokand.github.io/issues/3
https://bugzilla.mozilla.org/show_bug.cgi?id=1423013

Safari and Firefox today size the layout/fixed viewport to the ICB width but Chrome sizes it to the content size. Firefox and Safari's model is more rational but Firefox has run into web compat issues in https://bugzilla.mozilla.org/show_bug.cgi?id=1123938

We should collect data on how often this happens in the wild. In particular, how often content is wider than the ICB, and importantly, how often the page also has overflow-x: hidden, making that content unreachable.