We hadn't considered the following:
If the change index is stale, it's possible to return changes that
no longer exist, which will be very confusing for the user. To
avoid it, it's best to keep the behavior of sending the refs/changes
here, since any ref/change that is in the input exists. Alternatively,
we can also check with exactRef whether the ref exists, but doing so
10000 times will no longer be efficient.
The reverted changes (minus reformats) are I9a264b3 and I9fa8b389.
This is a manual revert since some reformats were not reverted.
Change-Id: I54778b22d92d4028f17777c7d61c87f992a2dcde
b5f6b3ed43