Add handling to respect role attribute in AXObjects.

LayoutTests/accessibility/role-attribute-expected.txt

Index: LayoutTests/accessibility/role-attribute-expected.txt
diff --git a/LayoutTests/accessibility/role-attribute-expected.txt b/LayoutTests/accessibility/role-attribute-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..99cabf84528914e37b188655d0c31778597a9b2f
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+++ b/LayoutTests/accessibility/role-attribute-expected.txt
@@ -0,0 +1,51 @@
+Explicit Item 1
+Explicit Item 2
+Explicit Item 3
+Implicit Item 1
+Implicit Item 2
+Implicit Item 3
+     
+End of test
+
+This tests that the role attribute is not missed.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+AXRole: AXWebArea AXValue: 
+    AXRole: AXRadioGroup AXValue: 
+        AXRole: AXRadioButton AXValue: 
+        AXRole: AXRadioButton AXValue: 
+        AXRole: AXRadioButton AXValue: 
+    AXRole: AXList AXValue: 
+        AXRole: AXListItem AXValue: 
+            AXRole: AXListMarker AXValue: 1
+            AXRole: AXStaticText AXValue: Implicit Item 1
+                AXRole: AXInlineTextBox AXValue: Implicit Item 1
+        AXRole: AXListItem AXValue: 
+            AXRole: AXListMarker AXValue: 2
+            AXRole: AXStaticText AXValue: Implicit Item 2
+                AXRole: AXInlineTextBox AXValue: Implicit Item 2
+        AXRole: AXListItem AXValue: 
+            AXRole: AXListMarker AXValue: 3
+            AXRole: AXStaticText AXValue: Implicit Item 3
+                AXRole: AXInlineTextBox AXValue: Implicit Item 3
+    AXRole: AXGroup AXValue: 
+        AXRole: AXGroup AXValue: 
+            AXRole: AXTextField AXValue: Explicit Option 1
+            AXRole: AXTextField AXValue: Explicit Option 2
+        AXRole: AXListBox AXValue: 
+            AXRole: AXListBoxOption AXValue: Implicit Option 1
+            AXRole: AXListBoxOption AXValue: Implicit Option 2
+        AXRole: AXStatus AXValue: 
+        AXRole: AXProgressIndicator AXValue: 
+        AXRole: AXStatus AXValue: 5
+            AXRole: AXSliderThumb AXValue: 
+        AXRole: AXSlider AXValue: 5
+            AXRole: AXSliderThumb AXValue: 
+    AXRole: AXParagraph AXValue: 
+        AXRole: AXStaticText AXValue: End of test
+PASS successfullyParsed is true
+
+TEST COMPLETE
+