Add DumpAccessibilityTree tests (9 of 20)

Add DumpAccessibilityTree tests (9 of 20)

HTML Tag: summary, h1 to h6, thead, input-url, fieldset, audio, iframe
ARIA role: rowgroup, presentation
ARIA state/property: aria-valuemax

Other Fixes in this CL:

1. Under switch case AX_ROLE_GROUP only HTML li tag should have STATE_SYSTEM_READONLY
2. Also ROLE_SYSTEM_TABLE, _ROW, _ROWHEADER, _COLUMN, _COLUMNHEADER shouldn't have STATE_SYSTEM_READONLY
2. HTML Iframe tag should have ia_role_ as ROLE_SYSTEM_GROUPING and ia_state_ as STATE_SYSTEM_READONLY

BUG=170581
Committed: https://crrev.com/e8234c99de489f9572751188a671ec1fad36817c
Cr-Commit-Position: refs/heads/master@{#301806}

[shreeramk, 2014-10-28 19:07:30]

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

[shreeramk, 2014-10-28 19:07:32]

Please review the changes. 
Thanks!

[dmazzoni, 2014-10-29 07:15:46]

The CQ bit was checked by dmazzoni@chromium.org

[dmazzoni, 2014-10-29 07:15:47]

lgtm

https://codereview.chromium.org/683063002/diff/40001/content/test/data/access...
File content/test/data/accessibility/iframe.html (right):

https://codereview.chromium.org/683063002/diff/40001/content/test/data/access...
content/test/data/accessibility/iframe.html:7: <iframe src="iframesrc.html">
I'm slightly worried that this test will be flaky, because the main frame's load
complete is allowed to fire before the inner frame finishes loading.

If this test lands and doesn't cause any flakiness, it's fine with me.

If it does end up failing on any builders, try adding some text to the inner
frame, then use a @WAIT-FOR directive at the top, which will tell
DumpAccessibilityTree to keep waiting for more accessibility events until it
finds the given text.

[commit-bot: I haz the power, 2014-10-29 07:15:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/683063002/40001

[commit-bot: I haz the power, 2014-10-29 08:03:02]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2014-10-29 08:03:48]

Patchset 3 (id:??) landed as
https://crrev.com/e8234c99de489f9572751188a671ec1fad36817c
Cr-Commit-Position: refs/heads/master@{#301806}