Initial support for native accessibility in ARC

components/exo/shell_surface.cc

Index: components/exo/shell_surface.cc
diff --git a/components/exo/shell_surface.cc b/components/exo/shell_surface.cc
index 40fd30b14503b90eabadc448c3f7b96f2369cece..83dd4bbd5bb7e007f7242207a9ca978cf41416d5 100644
--- a/components/exo/shell_surface.cc
+++ b/components/exo/shell_surface.cc
@@ -23,6 +23,7 @@
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "components/exo/surface.h"
+#include "ui/accessibility/ax_node_data.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/cursor_client.h"
 #include "ui/aura/window.h"
@@ -871,6 +872,13 @@ gfx::Size ShellSurface::GetMinimumSize() const {
   return gfx::Size(1, 1);
 }
 
+void ShellSurface::GetAccessibleNodeData(ui::AXNodeData* node_data) {
+  int32_t id = GetWidget()->GetNativeWindow()->GetProperty(
+      aura::client::kAccessibleChildTreeIdKey);
+  if (id)
+    node_data->AddIntAttribute(ui::AX_ATTR_CHILD_TREE_ID, id);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // ash::wm::WindowStateObserver overrides: