Improve the notifications sent from AXTree updates.

content/browser/accessibility/browser_accessibility_manager_mac.mm

 // 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.
 
 #include "content/browser/accessibility/browser_accessibility_manager_mac.h"
 
 #import "base/logging.h"
 #import "content/browser/accessibility/browser_accessibility_cocoa.h"
 #import "content/browser/accessibility/browser_accessibility_mac.h"
 #include "content/common/accessibility_messages.h"
 
 namespace content {
 
 // static
 BrowserAccessibilityManager* BrowserAccessibilityManager::Create(
     const ui::AXTreeUpdate& initial_tree,
     BrowserAccessibilityDelegate* delegate,
     BrowserAccessibilityFactory* factory) {
   return new BrowserAccessibilityManagerMac(
       NULL, initial_tree, delegate, factory);
 }
 
 BrowserAccessibilityManagerMac::BrowserAccessibilityManagerMac(
     NSView* parent_view,
     const ui::AXTreeUpdate& initial_tree,
     BrowserAccessibilityDelegate* delegate,
     BrowserAccessibilityFactory* factory)
     : BrowserAccessibilityManager(delegate, factory),
-      parent_view_(parent_view),
-      created_live_region_(false) {
+      parent_view_(parent_view) {
   Initialize(initial_tree);
 }
 
 // static
 ui::AXTreeUpdate BrowserAccessibilityManagerMac::GetEmptyDocument() {
   ui::AXNodeData empty_document;
   empty_document.id = 0;
   empty_document.role = ui::AX_ROLE_ROOT_WEB_AREA;
   empty_document.state =
       1 << ui::AX_STATE_READ_ONLY;
@@ skipping 97 matching lines @@
       return;
     default:
       LOG(WARNING) << "Unknown accessibility event: " << event_type;
       return;
   }
   BrowserAccessibilityCocoa* native_node = node->ToBrowserAccessibilityCocoa();
   DCHECK(native_node);
   NSAccessibilityPostNotification(native_node, event_id);
 }
 
-void BrowserAccessibilityManagerMac::OnNodeCreationFinished(ui::AXNode* node) {
-  BrowserAccessibility* obj = GetFromAXNode(node);
-  if (obj && obj->HasStringAttribute(ui::AX_ATTR_LIVE_STATUS))
-    created_live_region_ = true;
-}
+void BrowserAccessibilityManagerMac::OnAtomicUpdateFinished(
+    bool root_changed, const std::vector<ui::AXTreeDelegate::Change>& changes) {
+  BrowserAccessibilityManager::OnAtomicUpdateFinished(root_changed, changes);
 
-void BrowserAccessibilityManagerMac::OnTreeUpdateFinished() {
-  if (!created_live_region_)
+  bool created_live_region = false;
+  for (size_t i = 0; i < changes.size(); ++i) {
+    BrowserAccessibility* obj = GetFromAXNode(changes[i].node);
+    if (obj && obj->HasStringAttribute(ui::AX_ATTR_LIVE_STATUS)) {
+      created_live_region = true;
+      break;
+    }
+  }
+
+  if (!created_live_region)
     return;
 
   // This code is to work around a bug in VoiceOver, where a new live
   // region that gets added is ignored. VoiceOver seems to only scan the
   // page for live regions once. By recreating the NSAccessibility
   // object for the root of the tree, we force VoiceOver to clear out its
   // internal state and find newly-added live regions this time.
   BrowserAccessibilityMac* root =
       static_cast<BrowserAccessibilityMac*>(GetRoot());
   root->RecreateNativeObject();
   NotifyAccessibilityEvent(ui::AX_EVENT_CHILDREN_CHANGED, root);
-
-  created_live_region_ = false;
 }
 
 }  // namespace content