Try |View::HandleAccessibleAction| before falling back to fixed actions.

ui/views/accessibility/ax_aura_obj_wrapper.cc

Index: ui/views/accessibility/ax_aura_obj_wrapper.cc
diff --git a/ui/views/accessibility/ax_aura_obj_wrapper.cc b/ui/views/accessibility/ax_aura_obj_wrapper.cc
new file mode 100644
index 0000000000000000000000000000000000000000..52acd4f094692d49cf3d5eb0133ad812b480104b
--- /dev/null
+++ b/ui/views/accessibility/ax_aura_obj_wrapper.cc
@@ -0,0 +1,13 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/views/accessibility/ax_aura_obj_wrapper.h"
+
+namespace views {
+
+bool AXAuraObjWrapper::HandleAccessibleAction(const ui::AXActionData& action) {
+  return false;
+}
+
+}  // namespace views