Test basic getDisplayMedia prompting behavior

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


PASS numberOfTimesGetUserMediaPromptHasBeenCalled() is 0

** Request an audio-only stream, the user should be prompted **
PASS numberOfTimesGetUserMediaPromptHasBeenCalled() is 1
PASS stream.getAudioTracks().length is 1
PASS stream.getVideoTracks().length is 0

** Request an video-only stream, the user should be prompted **
PASS numberOfTimesGetUserMediaPromptHasBeenCalled() is 2
PASS stream.getAudioTracks().length is 0
PASS stream.getVideoTracks().length is 1

** Request a stream with audio and video, the user should be prompted **
PASS numberOfTimesGetUserMediaPromptHasBeenCalled() is 3
PASS stream.getAudioTracks().length is 1
PASS stream.getVideoTracks().length is 1

** Request a stream with invalid constraints, the user should not be prompted **
PASS numberOfTimesGetUserMediaPromptHasBeenCalled() is 3
PASS stream is null
PASS err instanceof Error  is true
PASS err.name is "InvalidAccessError"

PASS successfullyParsed is true

TEST COMPLETE