Added Area-HTML label.

Added Triaged label.

This comment was originally written by @zoechi

As I learned from a discussion about another bug related to ownerDocument (ownerDocument.createElement()):
For imports the ownerDocument (a method of the base class in custom element) refers the imported html file (e.g. a custom control) not the main page (not 100% sure about this though) it is understadable that it has no cookies.
document is a public method of the polymer package referencing the main document which naturally has access to the cookies.
Please correct me if I'm wrong.

There are multiple documents in play for typical Polymer applications-

Each HTML import is a separate document and the contents of Template elements are also separate documents.

From custom elements, typically you'll see at least two instantiations-
  - The first will be the instance within the template contents. This is distinguishable because ownerDocument.defaultView will be null. Also enteredView will never be invoked.
  - The second is when the template is instanced and the element is added to the view. enteredView will be invoked and ownerDocument.defaultView will be true.

I assume that if the top-level document is used rather than a different one that it will work properly.

This comment was originally written by Erik.G...@gmail.com

The top-level document.cookie worked properly. I tested ownerDocument.cookie again with with build 30187 and polymer 0.9.0+1 using the same code, ownerDocument.cookie is now reading the top-level document cookie on restart. That being said, does it make sense to allow operations like getting/setting cookies on these other documents?

Removed Area-HTML label.
Added Area-Library, Library-Html labels.

With the pending question it's definitely an enhancement rather than a defect. I don't know if it's appropriate, but that seems more like a Polymer/Custom Elements question than a general dart:html issue. Put in a query to Polymer people.

Removed Type-Defect, Priority-Unassigned labels.
Added Type-Enhancement, Priority-Medium labels.

It seems like it would be very difficult to make that work in Polymer. So I'm going to call the original issue resolved and the generalization not planned.

Added NotPlanned label.