core-scroll-header-panel won't hide navigation bar on Android (stable and beta)

[tjsavage]

This is not a duplicate of #4 but related to #1 which is not fixed by Chrome beta for Android. :(
(but: everything is much smoother in Chrome beta - awesome work!)

1. Open
   http://www.polymer-project.org/components/core-scroll-header-panel/demo.html
   on Chrome for Android.
2. Scroll down.
3. Issue: The Chrome navigation bar will not hide automatically as it does on any other website.

I guess it has something to do with the header not being inside the scrollable element, so it might be fixed by fixing #1 - but I'm not sure about that.

[ebidel]

We should consider telling folks to use the Web App manifest.json. "display: standalone" removes browser chrome.

https://www.chromestatus.com/features/6488656873259008

[davenotik]

@ebidel, that doesn't seem to address the issue here. It seems manifest.json standardizes what's already possible in mobile browsers; for example we can already set <meta name="apple-mobile-web-app-capable" content="yes"> to make Safari full screen. But I've found that's confusing to users. Rather, we're talking about the standard mechanism where as you slide down the chrome gets out of the way. This works across most every website, but something about core-scroll-header-panel and related doesn't allow that to work. Please correct me if I'm missing something here.