AX: Improve AccessibilityTableCell isColumnHeaderCell function.
https://bugs.webkit.org/show_bug.cgi?id=138423

Patch by Andrzej Badowski <a.badowski@samsung.com> on 2014-11-14
Reviewed by Chris Fleizach.

Source/WebCore:

<th> cell in the zero row should be column header.

New tests are not necessary.

* accessibility/AccessibilityTableCell.cpp:
(WebCore::AccessibilityTableCell::isColumnHeaderCell):

LayoutTests:

Files of expected type are adapted to changes in the code of the function.

* accessibility/table-cells-roles-expected.txt:
* platform/efl/accessibility/table-attributes-expected.txt:
* platform/efl/accessibility/table-cells-expected.txt:
* platform/gtk/accessibility/table-attributes-expected.txt:
* platform/gtk/accessibility/table-cells-expected.txt:
* platform/mac/accessibility/table-attributes-expected.txt:
* platform/mac/accessibility/table-cells-expected.txt:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@176122 268f45cc-cd09-0410-ab3c-d52691b4dbfc