This idea came up when we were discussing general pin-updating mechanisms. We have a significant amount of use-cases where we want to create and land changes that only change a single file (ie DEPS rollers)

Apparently gerrit has an API for creating, and then creating file-edits. Probably this:
https://gerrit-review.googlesource.com/Documentation/rest-api-changes.html#put-edit-file

If we had a tool that wrapped these endpoints, it would obviate the need for any local checkouts when updating/rolling pins. For some use-cases (ie rollers in chromium/src.git) this could save a lot of resources (disk, network, etc).

This sounds like a infra>platform bug. (Or maybe infra>codereview? or maybe infra>git?)