Don't store raw pointers in BrowserAccessibilityManager::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 423 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 list of accessibility events to fire based on changes to the
-  // accessibility tree. Only used within the scope of one call to
-  // OnAccessibilityEvents, so it's safe to store raw pointers.
-  std::vector<std::pair<ui::AXEvent, BrowserAccessibility*>> tree_events_;
+  // 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_;
 
   // 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 35 matching lines @@
   // used and it won't be updated from the delegate.
   bool use_custom_device_scale_factor_for_testing_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_H_