AX: Allow requesting the full plain text for an object with textUnderElement()
https://bugs.webkit.org/show_bug.cgi?id=105214

Reviewed by Chris Fleizach.

Source/WebCore:

Allow specifying different function modes for textUnderElement(),
so we can effectively ask for the "normal" result (e.g to retrieve
test to be exposed as the 'title') or for the full text under the
element (without omitting any child in the subtree). This is
needed for the implementation of atk_text_get_text() in GTK/EFL.

* accessibility/AccessibilityObject.h: Add new enumeration to
specify the different modes for textUnderElement().
(WebCore::AccessibilityObject::textUnderElement): Added parameter.

* accessibility/AccessibilityNodeObject.cpp:
(WebCore::shouldUseAccessiblityObjectInnerText): Always return
'true' when using the "include all children" mode.
(WebCore::AccessibilityNodeObject::textUnderElement): Updated call
to shouldUseAccessiblityObjectInnerText().
* accessibility/AccessibilityNodeObject.h:

* accessibility/AccessibilityRenderObject.cpp:
(WebCore::AccessibilityRenderObject::textUnderElement): Removed
GTK specific code and expand the usage of text iterators beyond
text render objects, using it also when in the "include all
children" mode.
* accessibility/AccessibilityRenderObject.h:

* accessibility/atk/AccessibilityObjectAtk.cpp:
(WebCore::AccessibilityObject::getLengthForTextRange): Updated
call to textUnderElement(), preserving the previous behavior.

* accessibility/atk/WebKitAccessibleInterfaceText.cpp:
(webkitAccessibleTextGetText): Updated call to textUnderElement(),
using the "include all children" mode.

LayoutTests:

Removed tests that are not longer expected to fail.

* platform/gtk/TestExpectations: Removed tests.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@152537 268f45cc-cd09-0410-ab3c-d52691b4dbfc