Add conversion rule for aria-grabbed attributes.

content/renderer/accessibility/blink_ax_tree_source.cc

Index: content/renderer/accessibility/blink_ax_tree_source.cc
diff --git a/content/renderer/accessibility/blink_ax_tree_source.cc b/content/renderer/accessibility/blink_ax_tree_source.cc
index 03207acec92e2112fe84b65d5edd83a80e94e40d..b6b93c6be142ecb3f30a38c44a2a6b32b19255bd 100644
--- a/content/renderer/accessibility/blink_ax_tree_source.cc
+++ b/content/renderer/accessibility/blink_ax_tree_source.cc
@@ -378,6 +378,12 @@ void BlinkAXTreeSource::SerializeNode(blink::WebAXObject src,
       }
     }
 
+    blink::WebAXOptionalBool optionalBool = src.isAriaGrabbed();
+    if (optionalBool == blink::WebAXOptionalBoolFalse)
+      dst->AddBoolAttribute(ui::AX_ATTR_GRABBED, false);
+    else if (optionalBool == blink::WebAXOptionalBoolTrue)
+      dst->AddBoolAttribute(ui::AX_ATTR_GRABBED, true);
+
     // ARIA role.
     if (element.hasAttribute("role")) {
       dst->AddStringAttribute(ui::AX_ATTR_ROLE,