Fix detached callback and add isAttached to SkyElements.

Fix detached callback and add isAttached to SkyElements.

There was a typo in the name of the detached callback which is now fixed,
and also allow querying if an element is attached.

R=rafaelw@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/17d0a7352d7dd039140e621bd00e966b83d77d4c

[esprehn, 2014-12-19 22:54:10]

esprehn@chromium.org changed reviewers:
+ eseidel@chromium.org, rafaelw@chromium.org

[rafaelw, 2014-12-19 23:22:56]

lgtm w/ nit

https://codereview.chromium.org/806133003/diff/40001/sky/framework/sky-elemen...
File sky/framework/sky-element/sky-element.sky (right):

https://codereview.chromium.org/806133003/diff/40001/sky/framework/sky-elemen...
sky/framework/sky-element/sky-element.sky:10: var kInternal =
Symbol("SkyElementInternal");
nit: let's not use this kind of naming. How about 'internalSymbol'?

[esprehn, 2014-12-19 23:27:47]

On 2014/12/19 at 23:22:56, rafaelw wrote:
> lgtm w/ nit
> 
>
https://codereview.chromium.org/806133003/diff/40001/sky/framework/sky-elemen...
> File sky/framework/sky-element/sky-element.sky (right):
> 
>
https://codereview.chromium.org/806133003/diff/40001/sky/framework/sky-elemen...
> sky/framework/sky-element/sky-element.sky:10: var kInternal =
Symbol("SkyElementInternal");
> nit: let's not use this kind of naming. How about 'internalSymbol'?

That came from abarth, internalSymbol seems really long, is there a reason you
don't like the "k" prefix?

[esprehn, 2015-01-05 20:54:36]

On 2014/12/19 at 23:27:47, esprehn wrote:
> On 2014/12/19 at 23:22:56, rafaelw wrote:
> > lgtm w/ nit
> > 
> >
https://codereview.chromium.org/806133003/diff/40001/sky/framework/sky-elemen...
> > File sky/framework/sky-element/sky-element.sky (right):
> > 
> >
https://codereview.chromium.org/806133003/diff/40001/sky/framework/sky-elemen...
> > sky/framework/sky-element/sky-element.sky:10: var kInternal =
Symbol("SkyElementInternal");
> > nit: let's not use this kind of naming. How about 'internalSymbol'?
> 
> That came from abarth, internalSymbol seems really long, is there a reason you
don't like the "k" prefix?

For now I'm going to just use a public boolean property, lets solve the private
state issue and symbols later.

[esprehn, 2015-01-05 20:54:47]

Committed patchset #4 (id:60001) manually as
17d0a7352d7dd039140e621bd00e966b83d77d4c (presubmit successful).

[abarth-chromium, 2015-01-05 20:58:32]

On 2014/12/19 at 23:27:47, esprehn wrote:
> That came from abarth,

I was just cargo culting the C++ style guide.  I don't know proper JavaScript
style.