If in progress, halts the UnityWebRequest as soon as possible.
This method may be called at any time. If the UnityWebRequest has not already completed, the UnityWebRequest will halt uploading or downloading data as soon as possible. Aborted UnityWebRequests are considered to have encountered a system error. The isError property will return true and the error property will be "User Aborted".
If this method is called prior to calling Send, then the UnityWebRequest will abort immediately after the call to Send.
Calls to this method have no effect after this UnityWebRequest has encountered a different error, or has successfully finished communicating with the remote server.