Implement computedRole and computedName (behind a flag)

Source/modules/accessibility/AXObject.h

Index: Source/modules/accessibility/AXObject.h
diff --git a/Source/modules/accessibility/AXObject.h b/Source/modules/accessibility/AXObject.h
index 84f243e58730ce0a4f0716ab79d097a653c64df3..d01fa2fb55520a0dff7f5ce83ff04562c44bf2f5 100644
--- a/Source/modules/accessibility/AXObject.h
+++ b/Source/modules/accessibility/AXObject.h
@@ -52,6 +52,7 @@ class Widget;
 typedef unsigned AXID;
 
 enum AccessibilityRole {
+    NoRole = 0,

[dmazzoni, 2014/12/03 23:32:13]

We already have UnknownRole, can that work?

[aboxhall, 2014/12/08 23:50:59]

Maybe... though this is more like "no role because there's no AX object".

     AlertDialogRole = 1,
     AlertRole,
     AnnotationRole,
@@ -169,6 +170,7 @@ enum AccessibilityRole {
     UserInterfaceTooltipRole,
     WebAreaRole,
     WindowRole,
+    NumRoles
 };
 
 enum AccessibilityTextSource {
@@ -578,6 +580,7 @@ public:
     static bool isARIAInput(AccessibilityRole);
     static AccessibilityRole ariaRoleToWebCoreRole(const String&);
     static IntRect boundingBoxForQuads(RenderObject*, const Vector<FloatQuad>&);
+    static const AtomicString& roleName(const AccessibilityRole role);
 
 protected:
     AXID m_id;