Implement getLocationInfoForPosition for javascript ASTs

[TimvdLippe]

To be able to implement autocompletion of various Javascript features (for example this.$.), we need an equivalent of the traversal of the HTML AST, but then for a Javascript AST.

Usage of this traversal will probably to first invoke getLocationInfoForPosition for the HTML AST. If the return is scriptTagContents, retrieve the AST of the Node and invoke the second function which traverses the AST.

[tedium-bot]

Issue migrated to polymer/tools#478

[aomarks]

Re-opening because this original issue is now transferred and canonical again.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically closed after being marked stale. If you're still facing this problem with the above solution, please comment and we'll reopen!