a11y: Exclude children of nested keyboard accessible controls from a11y tree.

ui/views/accessibility/native_view_accessibility_mac.mm

Index: ui/views/accessibility/native_view_accessibility_mac.mm
diff --git a/ui/views/accessibility/native_view_accessibility_mac.mm b/ui/views/accessibility/native_view_accessibility_mac.mm
index 243c773bcb7e68715b4707d801809a9fb0f54618..c543d453ebc700b67fe4d7fc7ecb0968d7e21e5f 100644
--- a/ui/views/accessibility/native_view_accessibility_mac.mm
+++ b/ui/views/accessibility/native_view_accessibility_mac.mm
@@ -21,17 +21,11 @@ std::unique_ptr<NativeViewAccessibility> NativeViewAccessibility::Create(
 NativeViewAccessibilityMac::NativeViewAccessibilityMac(View* view)
     : NativeViewAccessibilityBase(view) {}
 
-gfx::NativeViewAccessible NativeViewAccessibilityMac::GetParent() {
-  if (view_->parent())
-    return view_->parent()->GetNativeViewAccessible();
-
+gfx::NativeViewAccessible
+NativeViewAccessibilityMac::GetNativeViewAccessibleForWidget() {
   if (view_->GetWidget())
     return view_->GetWidget()->GetNativeView();
-
-  if (parent_widget_)
-    return parent_widget_->GetRootView()->GetNativeViewAccessible();
-
-  return nullptr;
+  return NativeViewAccessibilityBase::GetNativeViewAccessibleForWidget();
 }
 
 }  // namespace views