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

ui/accessibility/platform/test_ax_node_wrapper.cc

Index: ui/accessibility/platform/test_ax_node_wrapper.cc
diff --git a/ui/accessibility/platform/test_ax_node_wrapper.cc b/ui/accessibility/platform/test_ax_node_wrapper.cc
index c639e0879bf70f436f1a807c98360467db7a66bc..1d62a5e00cd89b74e595033faba20c4d4bfe232c 100644
--- a/ui/accessibility/platform/test_ax_node_wrapper.cc
+++ b/ui/accessibility/platform/test_ax_node_wrapper.cc
@@ -111,6 +111,10 @@ gfx::NativeViewAccessible TestAXNodeWrapper::GetFocus() {
   return nullptr;
 }
 
+bool TestAXNodeWrapper::IsIgnored() {
+  return false;
+}
+
 gfx::AcceleratedWidget
 TestAXNodeWrapper::GetTargetForNativeAccessibilityEvent() {
   return gfx::kNullAcceleratedWidget;