Test File.lastModifiedDate returns null if the information is not available.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".

PASS event.dataTransfer contains a File object on drop.
PASS lastModifiedDate is not null
PASS lastModifiedDate is >= testStartTime
PASS (new Date()).getTime() is >= lastModifiedDate
PASS successfullyParsed is true

TEST COMPLETE