Automatically fire AX events on Mac based on tree changes

ui/accessibility/ax_tree_unittest.cc

 // Copyright 2013 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/accessibility/ax_tree.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
@@ skipping 25 matching lines @@
 
 class FakeAXTreeDelegate : public AXTreeDelegate {
  public:
   FakeAXTreeDelegate()
       : tree_data_changed_(false),
         root_changed_(false) {}
 
   void OnNodeDataWillChange(AXTree* tree,
                             const AXNodeData& old_node_data,
                             const AXNodeData& new_node_data) override {}
-  void OnTreeDataChanged(AXTree* tree) override {
+  void OnTreeDataChanged(AXTree* tree,
+                         const ui::AXTreeData& old_data,
+                         const ui::AXTreeData& new_data) override {
     tree_data_changed_ = true;
   }
-
   void OnNodeWillBeDeleted(AXTree* tree, AXNode* node) override {
     deleted_ids_.push_back(node->id());
   }
 
   void OnSubtreeWillBeDeleted(AXTree* tree, AXNode* node) override {
     subtree_deleted_ids_.push_back(node->id());
   }
 
   void OnNodeWillBeReparented(AXTree* tree, AXNode* node) override {}
 
@@ skipping 717 matching lines @@
       fake_delegate2.attribute_change_log();
   ASSERT_EQ(3U, change_log2.size());
   EXPECT_EQ("controlsIds changed from 2,2 to ", change_log2[0]);
   EXPECT_EQ("detailsIds changed from 3 to 2,2", change_log2[1]);
   EXPECT_EQ("flowtoIds changed from  to 3", change_log2[2]);
 
   tree.SetDelegate(NULL);
 }
 
 }  // namespace ui