Different uiScrollViewport schemes when using as a component

I am trying to use great ui-scroll module inside one of the components. This is a (surprise!) list, but i need to show it both inside window (no viewport) or inside popup (with viewport).

The only way I know to tell ui-scroll about viewport is `ui-scroll-viewport` attribute. And the only way I can tell Angular about optional attribute is `ng-attr-` prefix. I want it to be optional attribute, since I hate to copy-paste the same code in ng-switches.

And this is a place when things get interesting. According to https://github.com/angular/angular.js/issues/16441 ui-scroll gets information about `ui-scroll-viewport` attribute before evaluation of `ng-attr-ui-scroll-viewport` value.

May be someone will point me to more "right" solution. But for now I had to patch ui-scroll.js file.

1) I send the `max-height` style inside some param to the component
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