Exposing correct state for summary element depending on open attribute.

Exposing correct state for summary element depending on open attribute.

Mac:
In the Mac accessibility API on the summary element (AXDisclosureTriangle), set AXExpanded property to NO.
When the details element content is shown, on the summary element (AXDisclosureTriangle), set theAXExpanded property to YES.

Win:
In the IA2 accessibility API on the summary element (ROLE_SYSTEM_PUSHBUTTON), set STATE_SYSTEM_COLLAPSED.
When the details element content is shown, on the summary element (ROLE_SYSTEM_PUSHBUTTON), set STATE_SYSTEM_EXPANDED.

How hidden nd show states is reflected for details element?
The hidden and shown states of the details element content is reflected by the absence or presence of the open attribute.

This is in accordance with the spec http://rawgit.com/w3c/aria/master/html-aam/html-aam.html#summary-and-details-elements

BUG=282016
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=185050

[shreeramk, 2014-11-10 12:06:45]

shreeram.k@samsung.com changed reviewers:
+ aboxhall@chromium.org, dmazzoni@chromium.org

[shreeramk, 2014-11-10 12:06:45]

Please review.
Thanks!

[dmazzoni, 2014-11-10 17:09:22]

The CQ bit was checked by dmazzoni@chromium.org

[dmazzoni, 2014-11-10 17:09:22]

lgtm

[commit-bot: I haz the power, 2014-11-10 17:09:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/712983002/1

[commit-bot: I haz the power, 2014-11-10 17:50:25]

Committed patchset #1 (id:1) as 185050