There is a lot of talk online about storage.googleapis.com hosting malicious content, these reports are partly true.
The reason for this is that this domain is used to host files for Google Storage, a bit like Amazon buckets or any other web space provider.
Because you can get a free trial with this service it can be misused. Although the URL itself is safe, clean and genuine, the content added by any users of this platform maybe malicious.
If you are unsure if a URL is safe to use you can check it with Virus Total.
The domain name storage.googleapis.com is owned by Google – WhoIs details here.
Google Storage stores objects that are organized into buckets (as Amazon S3 does) identified within each bucket by a unique, user-assigned key. All requests are authorized using an access control list associated with each bucket and object. Bucket names and keys are chosen so that objects are addressable using HTTP URLs.