Add condition for checking AXExpanded on mac.

content/browser/accessibility/browser_accessibility_cocoa.mm

Index: content/browser/accessibility/browser_accessibility_cocoa.mm
diff --git a/content/browser/accessibility/browser_accessibility_cocoa.mm b/content/browser/accessibility/browser_accessibility_cocoa.mm
index ac81de7ab39d3f8fd4e8175fd59c8d220404de75..4ea39a3dd192711857963dd0d811b04c2938c45c 100644
--- a/content/browser/accessibility/browser_accessibility_cocoa.mm
+++ b/content/browser/accessibility/browser_accessibility_cocoa.mm
@@ -1190,7 +1190,6 @@ NSDictionary* attributeToMethodNameMap = nil;
       NSAccessibilityChildrenAttribute,
       NSAccessibilityDescriptionAttribute,
       NSAccessibilityEnabledAttribute,
-      NSAccessibilityExpandedAttribute,
       NSAccessibilityFocusedAttribute,
       NSAccessibilityHelpAttribute,
       NSAccessibilityLinkedUIElementsAttribute,
@@ -1319,6 +1318,14 @@ NSDictionary* attributeToMethodNameMap = nil;
         nil]];
   }
 
+  //Add expanded attribute only if it has expanded or collapsed state.
+  if (GetState(browserAccessibility_,ui::AX_STATE_EXPANDED) ||
+        GetState(browserAccessibility_,ui::AX_STATE_COLLAPSED)) {
+    [ret addObjectsFromArray:[NSArray arrayWithObjects:
+        NSAccessibilityExpandedAttribute,
+        nil]];
+  }
+
   // Title UI Element.
   if (browserAccessibility_->HasIntAttribute(ui::AX_ATTR_TITLE_UI_ELEMENT) ||
       (browserAccessibility_->HasIntListAttribute(ui::AX_ATTR_LABELLEDBY_IDS) &&