IBlob
Represents a binary large object.
http://dev.w3.org/2006/webapi/FileAPI/#dfn-Blob
Gets the stream to the file.
Gets if the stream to the blob is closed.
Gets the length of the blob.
Gets the mime-type of the blob.
void Close()
Closes the stream to the blob.
Slices a subset of the blob into a another blob.