Support html br element in AX Tree.

Source/modules/accessibility/AXRenderObject.cpp

 /*
 * Copyright (C) 2008 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 261 matching lines @@
     if ((m_ariaRole = determineAriaRoleAttribute()) != UnknownRole)
         return m_ariaRole;
 
     Node* node = m_renderer->node();
     RenderBoxModelObject* cssBox = renderBoxModelObject();
 
     if ((cssBox && cssBox->isListItem()) || isHTMLLIElement(node))
         return ListItemRole;
     if (m_renderer->isListMarker())
         return ListMarkerRole;
+    if (m_renderer->isBR())
+        return LineBreakRole;
     if (isHTMLLegendElement(node))
         return LegendRole;
     if (m_renderer->isText())
         return StaticTextRole;
     if (cssBox && isImageOrAltText(cssBox, node)) {
         if (node && node->isLink())
             return ImageMapRole;
         if (isHTMLInputElement(node))
             return ariaHasPopup() ? PopUpButtonRole : ButtonRole;
         if (isSVGImage())
@@ skipping 285 matching lines @@
         if (parent->isBoxModelObject() && toRenderBoxModelObject(parent)->isMenuList())
             return true;
     }
 
     // find out if this element is inside of a label element.
     // if so, it may be ignored because it's the label for a checkbox or radio button
     AXObject* controlObject = correspondingControlForLabelElement();
     if (controlObject && !controlObject->exposesTitleUIElement() && controlObject->isCheckboxOrRadio())
         return true;
 
+    if (m_renderer->isBR())
+        return false;
+
     // NOTE: BRs always have text boxes now, so the text box check here can be removed
     if (m_renderer->isText()) {
         // static text beneath MenuItems and MenuButtons are just reported along with the menu item, so it's ignored on an individual level
         AXObject* parent = parentObjectUnignored();
         if (parent && (parent->ariaRoleAttribute() == MenuItemRole || parent->ariaRoleAttribute() == MenuButtonRole))
             return true;
         RenderText* renderText = toRenderText(m_renderer);
         if (m_renderer->isBR() || !renderText->firstTextBox())
             return true;
 
@@ skipping 1811 matching lines @@
         if (label && label->renderer()) {
             LayoutRect labelRect = axObjectCache()->getOrCreate(label)->elementRect();
             result.unite(labelRect);
         }
     }
 
     return result;
 }
 
 } // namespace blink