Update browser cache of accessibility tree on renderer sub-tree changes....

chrome/browser/browser_accessibility_manager_win.h

 // Copyright (c) 2010 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 CHROME_BROWSER_BROWSER_ACCESSIBILITY_MANAGER_WIN_H_
 #define CHROME_BROWSER_BROWSER_ACCESSIBILITY_MANAGER_WIN_H_
 #pragma once
 
 #include <atlbase.h>
 #include <atlcom.h>
 #include <oleacc.h>
 
+#include <hash_map>
+#include <vector>
+
 #include "base/hash_tables.h"
 #include "base/scoped_comptr_win.h"
 #include "base/scoped_ptr.h"
 #include "webkit/glue/webaccessibility.h"
 
 class BrowserAccessibility;
 
 class BrowserAccessibilityFactory {
  public:
   virtual ~BrowserAccessibilityFactory() {}
 
   // Create an instance of BrowserAccessibility and return a new
   // reference to it.
   virtual BrowserAccessibility* Create();
 };
 
 // Class that can perform actions on behalf of the BrowserAccessibilityManager.
 class BrowserAccessibilityDelegate {
  public:
   virtual ~BrowserAccessibilityDelegate() {}
   virtual void SetAccessibilityFocus(int acc_obj_id) = 0;
   virtual void AccessibilityDoDefaultAction(int acc_obj_id) = 0;
+  virtual void AccessibilityObjectChildrenChangeAck() = 0;
 };
 
 // Manages a tree of BrowserAccessibility objects.
 class BrowserAccessibilityManager {
  public:
   BrowserAccessibilityManager(
       HWND parent_hwnd,
       const webkit_glue::WebAccessibility& src,
       BrowserAccessibilityDelegate* delegate,
       BrowserAccessibilityFactory* factory = new BrowserAccessibilityFactory());
 
   virtual ~BrowserAccessibilityManager();
 
   // Return a pointer to the root of the tree, does not make a new reference.
   BrowserAccessibility* GetRoot();
 
+  // Removes the BrowserAccessibility child_id from the manager.
+  void Remove(LONG child_id);
+
   // Return a pointer to the object corresponding to the given child_id,
   // does not make a new reference.
   BrowserAccessibility* GetFromChildID(LONG child_id);
 
   // Get a the default IAccessible for the parent window, does not make a
   // new reference.
   IAccessible* GetParentWindowIAccessible();
 
   // Get the parent window.
   HWND GetParentHWND();
 
   // Return the object that has focus, if it's a descandant of the
   // given root (inclusive). Does not make a new reference.
   BrowserAccessibility* GetFocus(BrowserAccessibility* root);
 
   // Tell the renderer to set focus to this node.
   void SetFocus(const BrowserAccessibility& node);
 
   // Tell the renderer to do the default action for this node.
   void DoDefaultAction(const BrowserAccessibility& node);
 
-  // Called when the renderer process has notified us of a focus or state
-  // change. Send a notification to MSAA clients of the change.
+  // Called when the renderer process has notified us of a focus, state,
+  // or children change. Send a notification to MSAA clients of the change.
   void OnAccessibilityFocusChange(int acc_obj_id);
   void OnAccessibilityObjectStateChange(int acc_obj_id);
+  void OnAccessibilityObjectChildrenChange(
+      const std::vector<webkit_glue::WebAccessibility>& acc_changes);
 
  private:
+  // Returns the next MSAA child id.
+  static LONG GetNextChildID();
+
   // Recursively build a tree of BrowserAccessibility objects from
   // the WebAccessibility tree received from the renderer process.
   BrowserAccessibility* CreateAccessibilityTree(
       BrowserAccessibility* parent,
+      int child_id,
       const webkit_glue::WebAccessibility& src,
       int index_in_parent);
 
   // The parent window.
   HWND parent_hwnd_;
 
   // The object that can perform actions on our behalf.
   BrowserAccessibilityDelegate* delegate_;
 
   // Factory to create BrowserAccessibility objects (for dependency injection).
@@ skipping 16 matching lines @@
 
   // The next child ID to use; static so that they're global to the process.
   // Screen readers cache these IDs to see if they've seen the same object
   // before so we should avoid reusing them within the same project.
   static LONG next_child_id_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityManager);
 };
 
 #endif  // CHROME_BROWSER_BROWSER_ACCESSIBILITY_MANAGER_WIN_H_