https://bugs.webkit.org/show_bug.cgi?id=71263

Reviewed by Ryosuke Niwa.

Source/WebCore:

A non-native editable text element is an element with an ARIA role of "textbox", which is
set on an element which behaves like an editable text element (such as a textarea, text
input field or contenteditable text), but whose behaviour is controlled by the author rather
than the browser.

This change makes certain methods on Node, and related methods in htmlediting and
visible_units, aware of the notion that an element may be editable only from the point of
view of assistive technology (via the ARIA textbox role), via the EditableType enum added to
EditingBoundary.h.

This is so that AccessibilityObject::lineForPosition() can use previousLinePosition(), and
AccessibilityRenderObject::indexForVisiblePosition() can use highestEditableRoot(), in a way
that respects non-native editability.

Test: accessibility/textbox-role-reports-line-number.html

* accessibility/AXObjectCache.cpp:
(WebCore::AXObjectCache::rootAXEditableElement): Returns the root element which is
editable from the point of view of assistive technology, whether natively or otherwise.
(WebCore::AXObjectCache::nodeIsTextControl): Whether the given node is considered an
editable text element by assistive technology, natively or otherwise.
* accessibility/AccessibilityObject.cpp:
(WebCore::AccessibilityObject::lineForPosition): Modified to request the previous line
position in an element which is editable to Accessibility.
* accessibility/AccessibilityRenderObject.cpp:
(WebCore::AccessibilityRenderObject::indexForVisiblePosition): Modified to request the
highest root element which is editable to Accessibility.
* dom/Node.cpp:
(WebCore::Node::rendererIsEditableToAccessibility): Whether this node is editable to
Accessibility for the given EditableLevel.
(WebCore::Node::rootEditableElement): Overloaded version of this method which takes an
EditableType enum value indicating whether non-native editability is to be respected.
* dom/Node.h:
(WebCore::Node::rendererIsEditable): Overloaded version of this method which takes an
EditableType enum value indicating whether non-native editability is to be respected.
(WebCore::Node::rendererIsRichlyEditable):  Overloaded version of this method which takes
an EditableType enum value indicating whether non-native editability is to be respected.
* editing/EditingBoundary.h:
* editing/htmlediting.cpp:
(WebCore::highestEditableRoot): Added optional EditableType parameter.
(WebCore::isEditablePosition): Added optional EditableType parameter.
(WebCore::isRichlyEditablePosition): Added optional EditableType parameter.
(WebCore::editableRootForPosition): Added optional EditableType parameter.
* editing/htmlediting.h:
* editing/visible_units.cpp:
(WebCore::previousLeafWithSameEditability): Added optional EditableType parameter.
(WebCore::previousLinePosition): Added optional EditableType parameter.
(WebCore::nextLeafWithSameEditability): Added optional EditableType parameter.
(WebCore::nextLinePosition): Added optional EditableType parameter.
* editing/visible_units.h:

LayoutTests:

* accessibility/textbox-role-reports-line-number-expected.txt: Added.
* accessibility/textbox-role-reports-line-number.html: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@104276 268f45cc-cd09-0410-ab3c-d52691b4dbfc