Although `window.history` is present in the context of Chrome Packaged Apps, it is not allowed to
access `window.history.pushState` or `window.history.state`, resulting in errors when trying to
"sniff" history support.
This commit fixes it by detecting a Chrome Packaged App (through the presence of
`window.chrome.app.runtime`). Note that `window.chrome.app` is present in the context of "normal"
webpages as well, but it doesn't have the `runtime` property, which is only available to packaged
apps (e.g. see https://developer.chrome.com/apps/api_index).
(It also also contains some style changes for making the structure and layout of `$sniffer` tests
more consistent.)
Fixes#11932Closes#13945
Georgios Kalpakas
9f5526f861