[webcomponents] Sharing styles across custom elements (#282)

We are building a bunch of components for an internal project. These components share some common styles (like font-awesome fonts, custom css framework, etc). As of now, we are sharing these styles across components using /deep/ combinators. I understand from the [recent](https://www.w3.org/wiki/Webapps/WebComponentsApril2015Meeting) web components meeting that /deep/ combinator and other shadow piercing combinators are going to be removed. 

I understand that Shadow DOM provides style boundary and it also helps in abstracting the implementation details of the component. In my use case, I am more interested in the latter than the former. Though style boundary prevents accidental leakage of styles, I still find the ability to selectively pierce the components useful. 

Please suggest alternatives for being able to share styles across components. (Custom css properties and named parts model might not be suitable for this use case. I am interesting in sharing classes across components than configuring hooks for theming).

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/webcomponents/issues/282