When defining custom elements, check that the argument is a constructor

When defining custom elements, check that the argument is a constructor

BUG=594918
Committed: https://crrev.com/baf58e07fe7a17c3e8faff4b354b9901e62a5734
Cr-Commit-Position: refs/heads/master@{#394002}

[dominicc (has gone to gerrit), 2016-05-16 04:18:14]

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

[dominicc (has gone to gerrit), 2016-05-16 04:19:08]

PTAL

Kudos, jochen, for speedily implementing V8 Issue 4993--you rock.

[domenic, 2016-05-16 18:07:18]

lgtm.

Would have been ideal if this was on v8::Value instead of v8::Object so that you
could use it more like the spec does, instead of needing the check-if-object,
cast-to-object, check-if-constructor dance. But this certainly works.

[dominicc (has gone to gerrit), 2016-05-17 01:07:12]

The CQ bit was checked by dominicc@chromium.org

[commit-bot: I haz the power, 2016-05-17 01:07:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1983743002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1983743002/1

[commit-bot: I haz the power, 2016-05-17 01:11:59]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-17 01:13:40]

Description was changed from

==========
When defining custom elements, check that the argument is a constructor

BUG=594918
==========

to

==========
When defining custom elements, check that the argument is a constructor

BUG=594918

Committed: https://crrev.com/baf58e07fe7a17c3e8faff4b354b9901e62a5734
Cr-Commit-Position: refs/heads/master@{#394002}
==========

[commit-bot: I haz the power, 2016-05-17 01:13:41]

Patchset 1 (id:??) landed as
https://crrev.com/baf58e07fe7a17c3e8faff4b354b9901e62a5734
Cr-Commit-Position: refs/heads/master@{#394002}