Change some roles to "button" instead of "link" where it'd benefit users of

Change some roles to "button" instead of "link" where it'd benefit users of
assistive tecnologies (e.g. screenreaders).

Depends on https://codereview.chromium.org/668983004/.

BUG=none
R=aboxhall@chromium.org
TEST=more "button" and less "link" in voice feedback or other ATs

Committed: https://crrev.com/75a84f8a3b21f722e8e52be1f99d48ae0acaed90
Cr-Commit-Position: refs/heads/master@{#301375}

[Dan Beam, 2014-10-24 02:57:36]

this one is still unanswered:
https://codereview.chromium.org/668983004/diff/120001/chrome/browser/resource...

i think it can stay a link, but it's up to you

[Dan Beam, 2014-10-24 03:01:14]

On 2014/10/24 02:57:36, Dan Beam wrote:
> this one is still unanswered:
>
https://codereview.chromium.org/668983004/diff/120001/chrome/browser/resource...
> 
> i think it can stay a link, but it's up to you

aboxhall@ says:

"""
Link is probably fine for that one
on reflection
"""

[aboxhall, 2014-10-24 23:55:56]

lgtm

[Dan Beam, 2014-10-27 15:31:38]

The CQ bit was checked by dbeam@chromium.org

[commit-bot: I haz the power, 2014-10-27 15:33:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/671173008/20001

[commit-bot: I haz the power, 2014-10-27 16:17:28]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-10-27 16:18:13]

Patchset 2 (id:??) landed as
https://crrev.com/75a84f8a3b21f722e8e52be1f99d48ae0acaed90
Cr-Commit-Position: refs/heads/master@{#301375}