migrate_perf_baselines.js

function migrateBaselines(from_project, to_project){
    var migration_id = new ObjectId()
    print("using migration id", migration_id)
    var baselines = db.json.find({project_id:from_project,tag:{$exists:true, $ne:""}})
    while(baselines.hasNext()){
            var n = baselines.next()
            delete n._id
            n.project_id = to_project
            n.from_migration_id = migration_id
            db.json.insert(n)
    }
}