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shell/platform/windows/accessibility_root_node.cc

@@ -102,6 +102,7 @@ IFACEMETHODIMP AccessibilityRootNode::get_accChild(VARIANT var_child,
   } else if (child_id == kAlertChildId && alert_accessible_) {
     *disp_child = alert_accessible_;
   } else if (child_id < 0) {
+    // A negative child ID can be used to refer to an AX node directly by its ID.
     return window_accessible_->get_accChild(var_child, disp_child);
   } else {
     return E_FAIL;