Support html br element in AX Tree.

Source/modules/accessibility/AXRenderObject.cpp

Index: Source/modules/accessibility/AXRenderObject.cpp
diff --git a/Source/modules/accessibility/AXRenderObject.cpp b/Source/modules/accessibility/AXRenderObject.cpp
index 66d3e6796b5184777fd2cff57bb695dddfc471fc..2563e01d96556ee781bc63cff4aebb4c9f13827b 100644
--- a/Source/modules/accessibility/AXRenderObject.cpp
+++ b/Source/modules/accessibility/AXRenderObject.cpp
@@ -279,6 +279,8 @@ AccessibilityRole AXRenderObject::determineAccessibilityRole()
         return ListItemRole;
     if (m_renderer->isListMarker())
         return ListMarkerRole;
+    if (m_renderer->isBR())
+        return LineBreakRole;
     if (isHTMLLegendElement(node))
         return LegendRole;
     if (m_renderer->isText())
@@ -584,6 +586,9 @@ bool AXRenderObject::computeAccessibilityIsIgnored() const
     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