Replace undefined assert_undefined function.

Replace undefined assert_undefined function.

assert_undefined(v) was a convenience function for assert_equals(v, null) that
was lost when merging player-unresolved-times.html with the W3C startTime.html
test file in http://crrev.com/2141853002

BUG=623437
Committed: https://crrev.com/4e8c3bc91382a3a69b5ddf6287101a4d5f47f6c5
Cr-Commit-Position: refs/heads/master@{#405055}

[suzyh_UTC10 (ex-contributor), 2016-07-13 04:56:27]

suzyh@chromium.org changed reviewers:
+ nainar@chromium.org

[suzyh_UTC10 (ex-contributor), 2016-07-13 04:57:00]

Hey Naina,

Sorry I didn't catch this when you did the original CL. PTAL!

[nainar, 2016-07-13 05:01:24]

The CQ bit was checked by nainar@chromium.org

[nainar, 2016-07-13 05:01:24]

lgtm

[commit-bot: I haz the power, 2016-07-13 05:01:59]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-13 06:24:42]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-07-13 06:28:23]

Description was changed from

==========
Replace undefined assert_undefined function.

assert_undefined(v) was a convenience function for assert_equals(v, null) that
was lost when merging player-unresolved-times.html with the W3C startTime.html
test file in http://crrev.com/2141853002

BUG=623437
==========

to

==========
Replace undefined assert_undefined function.

assert_undefined(v) was a convenience function for assert_equals(v, null) that
was lost when merging player-unresolved-times.html with the W3C startTime.html
test file in http://crrev.com/2141853002

BUG=623437

Committed: https://crrev.com/4e8c3bc91382a3a69b5ddf6287101a4d5f47f6c5
Cr-Commit-Position: refs/heads/master@{#405055}
==========

[commit-bot: I haz the power, 2016-07-13 06:28:24]

Patchset 1 (id:??) landed as
https://crrev.com/4e8c3bc91382a3a69b5ddf6287101a4d5f47f6c5
Cr-Commit-Position: refs/heads/master@{#405055}