Make selection changes in a text field invalidate accessibility tree root.

content/renderer/accessibility/renderer_accessibility.cc

 // 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/renderer/accessibility/renderer_accessibility.h"
 
 #include <queue>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 168 matching lines @@
     // will update it.
     // TODO(dmazzoni): remove this as soon as
     // https://bugs.webkit.org/show_bug.cgi?id=73460 is fixed.
     last_scroll_offset_ = scroll_offset;
     if (!obj.equals(document.accessibilityObject())) {
       HandleAXEvent(document.accessibilityObject(),
                     ui::AX_EVENT_LAYOUT_COMPLETE);
     }
   }
 
+  if (event == ui::AX_EVENT_TEXT_SELECTION_CHANGED &&
+      obj.isFocused() &&
+      !obj.equals(document.accessibilityObject())) {
+    // Changing the text selection in a text field may invalidate
+    // the anchor/focus attributes on the tree root.  Send a generic
+    // notification to have it updated.
+    HandleAXEvent(document.accessibilityObject(), event);
+  }
+
   // Add the accessibility object to our cache and ensure it's valid.
   AccessibilityHostMsg_EventParams acc_event;
   acc_event.id = obj.axID();
   acc_event.event_type = event;
 
   // Discard duplicate accessibility events.
   for (uint32 i = 0; i < pending_events_.size(); ++i) {
     if (pending_events_[i].id == acc_event.id &&
         pending_events_[i].event_type == acc_event.event_type) {
       return;
@@ skipping 348 matching lines @@
 #ifndef NDEBUG
     LOG(WARNING) << "ShowContextMenu on invalid object id " << acc_obj_id;
 #endif
     return;
   }
 
   obj.showContextMenu();
 }
 
 }  // namespace content