Fix bug where multiple JSObject wrappers could be created for the same JsObject.

Fix bug where multiple JSObject wrappers could be created for the same JsObject.
Factory constructors for JSObject now set the _dartHtmlWrapper of the JsObject
so that it will be hard to have future bugs related to preserving JSObject.

BUG=

Committed: https://github.com/dart-lang/sdk/commit/c66c110b750000f411853a9d4dff9ca747b00291

[Jacob, 2016-01-19 18:59:28]

jacobr@google.com changed reviewers:
+ alanknight@google.com

[Jacob, 2016-01-19 18:59:29]

TBR

[Jacob, 2016-01-19 18:59:39]

Description was changed from

==========
Fix bug where multiple JSObject wrappers could be created for the same JsObject.
Factory constructors for JSObject now set the _dartHtmlWrapper of the JsObject
so that it will be hard to have future bugs related to preserving JSObject.

BUG=
==========

to

==========
Fix bug where multiple JSObject wrappers could be created for the same JsObject.
Factory constructors for JSObject now set the _dartHtmlWrapper of the JsObject
so that it will be hard to have future bugs related to preserving JSObject.

BUG=

Committed:
https://github.com/dart-lang/sdk/commit/c66c110b750000f411853a9d4dff9ca747b00291
==========

[Jacob, 2016-01-19 18:59:39]

Committed patchset #1 (id:1) manually as
c66c110b750000f411853a9d4dff9ca747b00291.

[Alan Knight, 2016-01-19 19:03:15]

lgtm