Add a helper function and update test results with ax role of table header.

content/browser/accessibility/browser_accessibility.h

Index: content/browser/accessibility/browser_accessibility.h
diff --git a/content/browser/accessibility/browser_accessibility.h b/content/browser/accessibility/browser_accessibility.h
index 6b6361df29d195c3914002d3398c029f2446faf0..e399b8604f59bc6ffd97bb004b2d65ea0e85fdd4 100644
--- a/content/browser/accessibility/browser_accessibility.h
+++ b/content/browser/accessibility/browser_accessibility.h
@@ -241,6 +241,9 @@ class CONTENT_EXPORT BrowserAccessibility {
   // Returns true if the bit corresponding to the given state enum is 1.
   bool HasState(ui::AXState state_enum) const;
 
+  // Returns true if this node is an cell or an table header.
+  bool IsCellOrTableHeaderRole() const;
+
   // Returns true if this node is an editable text field of any kind.
   bool IsEditableText() const;