Don't ignore landmark and related AXObjects, because they should be exposed to

Source/core/accessibility/AXObject.cpp

Index: Source/core/accessibility/AXObject.cpp
===================================================================
--- Source/core/accessibility/AXObject.cpp	(revision 164401)
+++ Source/core/accessibility/AXObject.cpp	(working copy)
@@ -183,6 +183,25 @@
     return role == ButtonRole || role == PopUpButtonRole || role == ToggleButtonRole;
 }
 
+bool AXObject::isLandmarkRelated() const
+{
+    switch (roleValue()) {
+    case ApplicationRole:
+    case ArticleRole:
+    case BannerRole:
+    case ComplementaryRole:
+    case ContentInfoRole:
+    case FooterRole:
+    case MainRole:
+    case NavigationRole:
+    case RegionRole:
+    case SearchRole:
+        return true;
+    default:
+        return false;
+    }
+}
+
 bool AXObject::isMenuRelated() const
 {
     switch (roleValue()) {