Prototype of Dart proxies for JS objects.

NOT FOR SUBMISSION.

Prototype of Dart proxies for JS objects.

BUG=

[blois, 2014-03-05 01:26:45]

Iteration #2 on this. Primary changes:

#1 Eliminated the .proxy named constructor and just using .created. Proxy causes
some problems because it's difficult to enforce that the two constructors are
used properly- that someone doesn't write something like:

class Foo {
  Foo.created() : super.proxy();
}

Also since classes would most likely function only in one context, it doesn't
seem necessary to have two constructors.

#2 Removed document.registerElementProxy and instead exposing a lower level
primitive 'document.createElementUpgrader'. This leaves it up to the
user/framework to know when to upgrade the element.

The timing for this could come from the element_created package, or
alternatively, Polymer/dart could negotiate a callback from Polymer/js when
elements are upgraded.

[blois, 2014-03-05 22:16:32]

On 2014/03/05 01:26:45, blois wrote:
> Iteration #2 on this. Primary changes:
> 
> #1 Eliminated the .proxy named constructor and just using .created. Proxy
causes
> some problems because it's difficult to enforce that the two constructors are
> used properly- that someone doesn't write something like:
> 
> class Foo {
>   Foo.created() : super.proxy();
> }
> 
> Also since classes would most likely function only in one context, it doesn't
> seem necessary to have two constructors.
> 
> #2 Removed document.registerElementProxy and instead exposing a lower level
> primitive 'document.createElementUpgrader'. This leaves it up to the
> user/framework to know when to upgrade the element.
> 
> The timing for this could come from the element_created package, or
> alternatively, Polymer/dart could negotiate a callback from Polymer/js when
> elements are upgraded.

Moving this over to https://codereview.chromium.org/177113014/ (drops the
package for hooking element creation), adds Dartium support.