AXRoleDescription is not exposed correctly for aside, main, nav element

content/test/data/accessibility/landmark-expected-mac.txt

Index: content/test/data/accessibility/landmark-expected-mac.txt
diff --git a/content/test/data/accessibility/landmark-expected-mac.txt b/content/test/data/accessibility/landmark-expected-mac.txt
index 036baaec0fa040ce9d6637ec7a43fd54359e8706..da31e63f07fe19aacca8b14e736cdc0c6a9828b9 100644
--- a/content/test/data/accessibility/landmark-expected-mac.txt
+++ b/content/test/data/accessibility/landmark-expected-mac.txt
@@ -1,27 +1,27 @@
-AXWebArea
-    AXGroup AXSubrole=AXLandmarkBanner
-        AXStaticText AXValue='This is a header element.'
-    AXGroup AXSubrole=AXLandmarkComplementary
-        AXStaticText AXValue='This is an aside element.'
-    AXGroup AXSubrole=AXLandmarkContentInfo
-        AXStaticText AXValue='This is an address element.'
-    AXGroup AXSubrole=AXLandmarkContentInfo
-        AXStaticText AXValue='This is a footer element.'
-    AXGroup AXSubrole=AXLandmarkMain
-        AXStaticText AXValue='This is a main element.'
-    AXGroup AXSubrole=AXLandmarkNavigation
-        AXStaticText AXValue='This is a nav element.'
-    AXGroup AXSubrole=AXLandmarkApplication
-        AXStaticText AXValue='This is an ARIA application landmark.'
-    AXGroup AXSubrole=AXLandmarkBanner
-        AXStaticText AXValue='This is an ARIA banner landmark.'
-    AXGroup AXSubrole=AXLandmarkComplementary
-        AXStaticText AXValue='This is an ARIA complementary landmark.'
-    AXGroup AXSubrole=AXLandmarkContentInfo
-        AXStaticText AXValue='This is an ARIA contentinfo landmark.'
-    AXGroup AXSubrole=AXLandmarkMain
-        AXStaticText AXValue='This is an ARIA main landmark.'
-    AXGroup AXSubrole=AXLandmarkNavigation
-        AXStaticText AXValue='This is an ARIA navigation landmark.'
-    AXGroup AXSubrole=AXLandmarkSearch
-        AXStaticText AXValue='This is an ARIA search landmark.'
+AXWebArea AXRoleDescription='HTML content'
+    AXGroup AXSubrole=AXLandmarkBanner AXRoleDescription='banner'
+        AXStaticText AXRoleDescription='text' AXValue='This is a header element.'
+    AXGroup AXSubrole=AXLandmarkComplementary AXRoleDescription='complementary'
+        AXStaticText AXRoleDescription='text' AXValue='This is an aside element.'
+    AXGroup AXSubrole=AXLandmarkContentInfo AXRoleDescription='address'
+        AXStaticText AXRoleDescription='text' AXValue='This is an address element.'
+    AXGroup AXSubrole=AXLandmarkContentInfo AXRoleDescription='footer'
+        AXStaticText AXRoleDescription='text' AXValue='This is a footer element.'
+    AXGroup AXSubrole=AXLandmarkMain AXRoleDescription='main'
+        AXStaticText AXRoleDescription='text' AXValue='This is a main element.'
+    AXGroup AXSubrole=AXLandmarkNavigation AXRoleDescription='navigation'
+        AXStaticText AXRoleDescription='text' AXValue='This is a nav element.'
+    AXGroup AXSubrole=AXLandmarkApplication AXRoleDescription='application'
+        AXStaticText AXRoleDescription='text' AXValue='This is an ARIA application landmark.'
+    AXGroup AXSubrole=AXLandmarkBanner AXRoleDescription='banner'
+        AXStaticText AXRoleDescription='text' AXValue='This is an ARIA banner landmark.'
+    AXGroup AXSubrole=AXLandmarkComplementary AXRoleDescription='complementary'
+        AXStaticText AXRoleDescription='text' AXValue='This is an ARIA complementary landmark.'
+    AXGroup AXSubrole=AXLandmarkContentInfo AXRoleDescription='contentinfo'
+        AXStaticText AXRoleDescription='text' AXValue='This is an ARIA contentinfo landmark.'
+    AXGroup AXSubrole=AXLandmarkMain AXRoleDescription='main'
+        AXStaticText AXRoleDescription='text' AXValue='This is an ARIA main landmark.'
+    AXGroup AXSubrole=AXLandmarkNavigation AXRoleDescription='navigation'
+        AXStaticText AXRoleDescription='text' AXValue='This is an ARIA navigation landmark.'
+    AXGroup AXSubrole=AXLandmarkSearch AXRoleDescription='search'
+        AXStaticText AXRoleDescription='text' AXValue='This is an ARIA search landmark.'