Pass null to attributeChangedCallback when there's no namespace URI

Pass null to attributeChangedCallback when there's no namespace URI

The DOM spec says attribute namespaces may be null, or non-empty [1].
We should accurately transmit those nulls to the
attributeChangedCallback [2]. We were converting null to empty string.

This also adds a test that non-null namespaces are transmitted, too.

[1] https://dom.spec.whatwg.org/#concept-attribute-namespace
[2] https://dom.spec.whatwg.org/#concept-element-attributes-change , etc.

BUG=643046
Committed: https://crrev.com/d39405eee528d5cec4edcb6dd9abfdc83b897fe8
Cr-Commit-Position: refs/heads/master@{#416458}

[dominicc (has gone to gerrit), 2016-09-02 04:16:35]

The CQ bit was checked by dominicc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-09-02 04:16:50]

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

[dominicc (has gone to gerrit), 2016-09-02 04:18:18]

dominicc@chromium.org changed reviewers:
+ hayato@chromium.org

[dominicc (has gone to gerrit), 2016-09-02 04:18:25]

PTAL

[commit-bot: I haz the power, 2016-09-02 05:38:24]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-09-02 05:38:25]

Dry run: Try jobs failed on following builders:
  win_chromium_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[dominicc (has gone to gerrit), 2016-09-02 06:11:07]

The CQ bit was checked by dominicc@chromium.org to run a CQ dry run

[hayato, 2016-09-02 06:11:10]

LGTM.

Could you check custom-elements/spec/upgrade-element.html? It looks failing.

[commit-bot: I haz the power, 2016-09-02 06:11:23]

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

[tkent, 2016-09-02 06:42:56]

tkent@chromium.org changed reviewers:
+ tkent@chromium.org

[tkent, 2016-09-02 06:42:57]

lgtm

[haraken, 2016-09-02 08:41:36]

bindings/ LGTM

[commit-bot: I haz the power, 2016-09-02 09:11:35]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-09-02 09:11:35]

Dry run: This issue passed the CQ dry run.

[dominicc (has gone to gerrit), 2016-09-03 22:15:50]

The CQ bit was checked by dominicc@chromium.org

[commit-bot: I haz the power, 2016-09-03 22:15:58]

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, 2016-09-04 00:13:09]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-09-04 00:16:09]

Description was changed from

==========
Pass null to attributeChangedCallback when there's no namespace URI

The DOM spec says attribute namespaces may be null, or non-empty [1].
We should accurately transmit those nulls to the
attributeChangedCallback [2]. We were converting null to empty string.

This also adds a test that non-null namespaces are transmitted, too.

[1] https://dom.spec.whatwg.org/#concept-attribute-namespace
[2] https://dom.spec.whatwg.org/#concept-element-attributes-change , etc.

BUG=643046
==========

to

==========
Pass null to attributeChangedCallback when there's no namespace URI

The DOM spec says attribute namespaces may be null, or non-empty [1].
We should accurately transmit those nulls to the
attributeChangedCallback [2]. We were converting null to empty string.

This also adds a test that non-null namespaces are transmitted, too.

[1] https://dom.spec.whatwg.org/#concept-attribute-namespace
[2] https://dom.spec.whatwg.org/#concept-element-attributes-change , etc.

BUG=643046

Committed: https://crrev.com/d39405eee528d5cec4edcb6dd9abfdc83b897fe8
Cr-Commit-Position: refs/heads/master@{#416458}
==========

[commit-bot: I haz the power, 2016-09-04 00:16:10]

Patchset 2 (id:??) landed as
https://crrev.com/d39405eee528d5cec4edcb6dd9abfdc83b897fe8
Cr-Commit-Position: refs/heads/master@{#416458}