Replace usage of setTimeout with step_timeout in XMLHttpRequest

[gsnedders]

This is expected to help test stability on slow configurations, as the
timeouts will be multiplied by the timeout multiplier.

Split out from #1816.

[wpt-pr-bot]

Notifying @Manishearth, @Ms2ger, @annevk, @caitp, @emilio, @hallvors, @ibelem, @jdm, @jungkees, @kangxu, @mathiasbynens, @ronkorving, and @wisniewskit. (Learn how reviewing works.)

[annevk]

Shouldn't this be test.step_timeout? Why is that not available in a worker?

[gsnedders]

@jgraham ^^?

[ghost]

View the complete job log.

Firefox (nightly channel)

Testing web-platform-tests at revision 75d10aa
Using browser at version BuildID 20170221110300; SourceStamp d84beb192e57e26846c82d3df3599381f4663792
Starting 10 test iterations
All results were stable

All results

7 tests ran

/XMLHttpRequest/xmlhttprequest-timeout-aborted.html

Subtest	Results	Messages
	OK
Timeout test: No events should fire for an unsent, unaborted request	PASS
Timeout test: time to abort is -1, timeout set at 2000	PASS
Timeout test: time to abort is 5000, timeout set at 2000	PASS

/XMLHttpRequest/xmlhttprequest-timeout-abortedonmain.html

Subtest	Results	Messages
	OK
Timeout test: time to abort is 0, timeout set at 2000	PASS
Timeout test: time to abort is 1000, timeout set at 2000	PASS

/XMLHttpRequest/xmlhttprequest-timeout-overrides.html

Subtest	Results	Messages
	OK
Timeout test: timeout disabled after initially set, original timeout at 5000, reset at 2000 to 0	PASS
Timeout test: timeout overrides load after a delay, original timeout at 5000, reset at 1000 to 2000	PASS
Timeout test: timeout enabled after initially disabled, original timeout at 0, reset at 2000 to 50000	PASS

/XMLHttpRequest/xmlhttprequest-timeout-overridesexpires.html

Subtest	Results	Messages
	OK
Timeout test: timeout set to expiring value after load fires, original timeout at 5000, reset at 4000 to 1000	PASS
Timeout test: timeout set to expired value before load fires, original timeout at 5000, reset at 2000 to 1100	PASS
Timeout test: timeout set to non-expiring value after timeout fires, original timeout at 1000, reset at 2000 to 500	PASS

/XMLHttpRequest/xmlhttprequest-timeout-simple.html

Subtest	Results	Messages
	OK
Timeout test: no time out scheduled, load fires normally, timeout scheduled at 0	PASS
Timeout test: load fires normally, timeout scheduled at 5000	PASS
Timeout test: timeout hit before load, timeout scheduled at 2000	PASS

/XMLHttpRequest/xmlhttprequest-timeout-synconmain.html

Subtest	Results	Messages
	OK
Timeout test: Synchronous XHR must not allow a timeout to be set - setting timeout must throw	PASS
Timeout test: Synchronous XHR must not allow a timeout to be set - calling open() after timeout is set must throw	PASS

/XMLHttpRequest/xmlhttprequest-timeout-twice.html

Subtest	Results	Messages
	OK
Timeout test: load fires normally with no timeout set, twice, original timeout at 0, reset at 2000 to 0	PASS
Timeout test: load fires normally with same timeout set twice, original timeout at 5000, reset at 2000 to 5000	PASS
Timeout test: timeout fires normally with same timeout set twice, original timeout at 2000, reset at 1000 to 2000	PASS

[ghost]

View the complete job log.

Chrome (unstable channel)

Testing web-platform-tests at revision 75d10aa
Using browser at version 58.0.3013.3 dev
Starting 10 test iterations
All results were stable

All results

7 tests ran

/XMLHttpRequest/xmlhttprequest-timeout-aborted.html

Subtest	Results	Messages
	OK
Timeout test: No events should fire for an unsent, unaborted request	PASS
Timeout test: time to abort is -1, timeout set at 2000	PASS
Timeout test: time to abort is 5000, timeout set at 2000	PASS

/XMLHttpRequest/xmlhttprequest-timeout-abortedonmain.html

Subtest	Results	Messages
	OK
Timeout test: time to abort is 0, timeout set at 2000	PASS
Timeout test: time to abort is 1000, timeout set at 2000	PASS

/XMLHttpRequest/xmlhttprequest-timeout-overrides.html

Subtest	Results	Messages
	OK
Timeout test: timeout disabled after initially set, original timeout at 5000, reset at 2000 to 0	PASS
Timeout test: timeout overrides load after a delay, original timeout at 5000, reset at 1000 to 2000	PASS
Timeout test: timeout enabled after initially disabled, original timeout at 0, reset at 2000 to 50000	PASS

/XMLHttpRequest/xmlhttprequest-timeout-overridesexpires.html

Subtest	Results	Messages
	OK
Timeout test: timeout set to expiring value after load fires, original timeout at 5000, reset at 4000 to 1000	PASS
Timeout test: timeout set to expired value before load fires, original timeout at 5000, reset at 2000 to 1100	PASS
Timeout test: timeout set to non-expiring value after timeout fires, original timeout at 1000, reset at 2000 to 500	PASS

/XMLHttpRequest/xmlhttprequest-timeout-simple.html

Subtest	Results	Messages
	OK
Timeout test: no time out scheduled, load fires normally, timeout scheduled at 0	PASS
Timeout test: load fires normally, timeout scheduled at 5000	PASS
Timeout test: timeout hit before load, timeout scheduled at 2000	PASS

/XMLHttpRequest/xmlhttprequest-timeout-synconmain.html

Subtest	Results	Messages
	OK
Timeout test: Synchronous XHR must not allow a timeout to be set - setting timeout must throw	PASS
Timeout test: Synchronous XHR must not allow a timeout to be set - calling open() after timeout is set must throw	PASS

/XMLHttpRequest/xmlhttprequest-timeout-twice.html

Subtest	Results	Messages
	OK
Timeout test: load fires normally with no timeout set, twice, original timeout at 0, reset at 2000 to 0	PASS
Timeout test: load fires normally with same timeout set twice, original timeout at 5000, reset at 2000 to 5000	PASS
Timeout test: timeout fires normally with same timeout set twice, original timeout at 2000, reset at 1000 to 2000	PASS

[annevk]

I guess I'm somewhat okay with landing this given that it doesn't change the results, but it still seems a little weird to only fix it outside workers.