Exposes the contents of math regions to screen readers

Exposes the children of math regions.

ARIA Implementation Guide 1.0 says that math should be mapped to ROLE_SYSTEM_EQUATION but we omitted to expose its children.
Mac works fine ones AX_ROLE_MATH is removed from the list of leaf objects.
Also checked with Safari and it does expose the children of role="math".
BUG=645168
R=dmazzoni@chromium.org
TESTED=manually

Review-Url: https://codereview.chromium.org/2715403002
Cr-Commit-Position: refs/heads/master@{#455673}
Committed: https://chromium.googlesource.com/chromium/src/+/54def8d1e3708b63e98e7db3a8e91554273b5561

[nektarios, 2017-02-27 23:23:55]

The CQ bit was checked by nektar@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-02-27 23:24:19]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[dmazzoni, 2017-02-27 23:51:44]

lgtm

[nektarios, 2017-02-27 23:54:47]

Ultimately, we should integrate with Jaws' and NVDA's math viewer.

[commit-bot: I haz the power, 2017-02-28 00:42:01]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-02-28 00:42:02]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[nektarios, 2017-03-09 02:58:28]

Description was changed from

==========
Temporarily maps role="math" to ROLE_SYSTEM_GROUPING and IA2-ROLE = PARAGRAPH to
work around the fact that Win screen readers from process children of
ROLE_SYSTEM_EQUATION.

ARIA Implementation Guide 1.0 says that math should be mapped to
ROLE_SYSTEM_EQUATION but Windows screen readers from traverse any children of
that role.
Mac works fine ones AX_ROLE_MATH is removed from the list of leaf objects.
Also checked with Safari and it does expose the children of role="math".
BUG=645168
R=dmazzoni@chromium.org
TESTED=manually using snippet attached to bug with Jaws NVDA and Voiceover,
browser test
==========

to

==========
Exposes the children of math regions.

ARIA Implementation Guide 1.0 says that math should be mapped to
ROLE_SYSTEM_EQUATION but we omitted to expose its children.
Mac works fine ones AX_ROLE_MATH is removed from the list of leaf objects.
Also checked with Safari and it does expose the children of role="math".
BUG=645168
R=dmazzoni@chromium.org
TESTED=manually
==========

[nektarios, 2017-03-09 03:05:17]

The CQ bit was checked by nektar@chromium.org

[nektarios, 2017-03-09 03:05:17]

The patchset sent to the CQ was uploaded after l-g-t-m from
dmazzoni@chromium.org
Link to the patchset: https://codereview.chromium.org/2715403002/#ps20001
(title: "Reverted workaround.")

[commit-bot: I haz the power, 2017-03-09 03:05:36]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-09 03:42:25]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-03-09 03:42:26]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[nektarios, 2017-03-09 04:23:49]

The CQ bit was checked by nektar@chromium.org

[nektarios, 2017-03-09 04:23:50]

The patchset sent to the CQ was uploaded after l-g-t-m from
dmazzoni@chromium.org
Link to the patchset: https://codereview.chromium.org/2715403002/#ps40001
(title: "Fixed test expectations.")

[commit-bot: I haz the power, 2017-03-09 04:24:03]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-09 05:24:24]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1489033429568010,
"parent_rev": "9ef3c96947ed010f07e1134c633b5761050fdf33", "commit_rev":
"54def8d1e3708b63e98e7db3a8e91554273b5561"}

[commit-bot: I haz the power, 2017-03-09 05:25:03]

Description was changed from

==========
Exposes the children of math regions.

ARIA Implementation Guide 1.0 says that math should be mapped to
ROLE_SYSTEM_EQUATION but we omitted to expose its children.
Mac works fine ones AX_ROLE_MATH is removed from the list of leaf objects.
Also checked with Safari and it does expose the children of role="math".
BUG=645168
R=dmazzoni@chromium.org
TESTED=manually
==========

to

==========
Exposes the children of math regions.

ARIA Implementation Guide 1.0 says that math should be mapped to
ROLE_SYSTEM_EQUATION but we omitted to expose its children.
Mac works fine ones AX_ROLE_MATH is removed from the list of leaf objects.
Also checked with Safari and it does expose the children of role="math".
BUG=645168
R=dmazzoni@chromium.org
TESTED=manually

Review-Url: https://codereview.chromium.org/2715403002
Cr-Commit-Position: refs/heads/master@{#455673}
Committed:
https://chromium.googlesource.com/chromium/src/+/54def8d1e3708b63e98e7db3a8e9...
==========

[commit-bot: I haz the power, 2017-03-09 05:25:04]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/chromium/src/+/54def8d1e3708b63e98e7db3a8e9...