Expose Value::GetList and Value(ListStorage) on ListValue

This change exposes the API introduced in r465517 also on the ListValue
class directly. This is for convenience, as it simplifies deprecating
the old raw pointer based APIs which eventually will lead to the
complete inlining of the ListValue class into Value.


Review-Url: https://codereview.chromium.org/2843783003
Cr-Commit-Position: refs/heads/master@{#467384}
3 files changed