Automatically fire AX events on Mac based on tree changes

content/browser/accessibility/browser_accessibility_manager.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_H_
 #define CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 325 matching lines @@
       int end_offset);
 
   // Accessors.
   ui::AXTreeIDRegistry::AXTreeID ax_tree_id() const { return ax_tree_id_; }
   float device_scale_factor() const { return device_scale_factor_; }
 
   // AXTreeDelegate implementation.
   void OnNodeDataWillChange(ui::AXTree* tree,
                             const ui::AXNodeData& old_node_data,
                             const ui::AXNodeData& new_node_data) override;
-  void OnTreeDataChanged(ui::AXTree* tree) override;
+  void OnTreeDataChanged(ui::AXTree* tree,
+                         const ui::AXTreeData& old_tree_data,
+                         const ui::AXTreeData& new_tree_data) override;
   void OnNodeWillBeDeleted(ui::AXTree* tree, ui::AXNode* node) override;
   void OnSubtreeWillBeDeleted(ui::AXTree* tree, ui::AXNode* node) override;
   void OnNodeWillBeReparented(ui::AXTree* tree, ui::AXNode* node) override;
   void OnSubtreeWillBeReparented(ui::AXTree* tree, ui::AXNode* node) override;
   void OnNodeCreated(ui::AXTree* tree, ui::AXNode* node) override;
   void OnNodeReparented(ui::AXTree* tree, ui::AXNode* node) override;
   void OnNodeChanged(ui::AXTree* tree, ui::AXNode* node) override;
   void OnAtomicUpdateFinished(
       ui::AXTree* tree,
       bool root_changed,
@@ skipping 79 matching lines @@
 
   // Factory to create BrowserAccessibility objects (for dependency injection).
   std::unique_ptr<BrowserAccessibilityFactory> factory_;
 
   // The underlying tree of accessibility objects.
   std::unique_ptr<ui::AXSerializableTree> tree_;
 
   // A mapping from a node id to its wrapper of type BrowserAccessibility.
   base::hash_map<int32_t, BrowserAccessibility*> id_wrapper_map_;
 
-  // A queue of accessibility events to fire based on changes to the
-  // accessibility tree. Each one is an event and a node id.
-  std::vector<std::pair<ui::AXEvent, int32_t>> tree_events_;
+  // A set of accessibility events to fire based on changes to the
+  // accessibility tree. It's represented as a map from node id
+  // to a set of events, which makes it easy to remove duplicates.
+  std::map<int32_t, std::set<ui::AXEvent>> tree_events_;
 
   // True if the user has initiated a navigation to another page.
   bool user_is_navigating_away_;
 
   // The on-screen keyboard state.
   OnScreenKeyboardState osk_state_;
 
   BrowserAccessibilityFindInPageInfo find_in_page_info_;
 
   // These are only used by the root BrowserAccessibilityManager of a
@@ skipping 39 matching lines @@
   // flakiness. See NeverSuppressOrDelayEventsForTesting() for details.
   static bool never_suppress_or_delay_events_for_testing_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_H_