"export" flag attribute documented in platform.js is actually "exportas"

[JanMiksovsky]

Minor discrepancy between code and comments: I was trying to get the various polyfill members exposed as a global by following the comments in platform.js, which indicate that you can do

<script src="platform.js" export=myglobal></script>

However, the actual flag is actually "exportas", not "export". (I wasn't sure whether the code or the comment should be fixed.)

[frankiefu]

This feature has been removed. Each polyfill now exposes its own scope; e.g. Platform, CustomElements, HTMLImports, etc.