Move some AX attrs from AXNodeData to AXTreeData.

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 77af2a2573f003d882a6301f5b6abead301b16a1..fbb76ca13be62ffd127756a73634856409f38a92 100644
--- a/ui/accessibility/platform/test_ax_node_wrapper.cc
+++ b/ui/accessibility/platform/test_ax_node_wrapper.cc
@@ -18,6 +18,7 @@ gfx::Vector2d g_offset;
 // A simple implementation of AXTreeDelegate to catch when AXNodes are
 // deleted so we can delete their wrappers.
 class TestAXTreeDelegate : public AXTreeDelegate {
+  void OnTreeDataChanged(AXTree* tree) override {}
   void OnNodeWillBeDeleted(AXTree* tree, AXNode* node) override {
     auto iter = g_node_to_wrapper_map.find(node);
     if (iter != g_node_to_wrapper_map.end()) {