[T-A]

If you wish to be precise, webcomponents.js was broken out of Polymer a while back. See e.g. [1]. In practice, if you use Polymer you are still using the polyfill + the elements from the catalog, as exemplified on [2].

[1] https://github.com/Polymer/HTMLImports

[2] https://www.polymer-project.org/1.0/

[spankalee]

You don't need the polyfills on Chrome.

[T-A]

Sure, but as long as browser coverage looks like this,

http://caniuse.com/#search=components

you have to include the polyfills anyway, unless you are targeting something like Electron or an intranet where everybody is guaranteed to be using Chrome.

That's why I put "standard" in quotes; although it's been around for years, it's really only supported by one widely used browser.