Ignore accessibility events fired on objects that aren't in the tree.

content/renderer/accessibility/blink_ax_tree_source.cc

 // Copyright 2014 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/blink_ax_tree_source.h"
 
 #include <set>
 
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
@@ skipping 82 matching lines @@
 
 }  // Anonymous namespace
 
 BlinkAXTreeSource::BlinkAXTreeSource(RenderViewImpl* render_view)
     : render_view_(render_view) {
 }
 
 BlinkAXTreeSource::~BlinkAXTreeSource() {
 }
 
+bool BlinkAXTreeSource::IsInTree(blink::WebAXObject node) const {
+  const blink::WebAXObject& root = GetRoot();
+  while (IsValid(node)) {
+    if (node.equals(root))
+      return true;
+    node = GetParent(node);
+  }
+  return false;
+}
+
 blink::WebAXObject BlinkAXTreeSource::GetRoot() const {
   return GetMainDocument().accessibilityObject();
 }
 
 blink::WebAXObject BlinkAXTreeSource::GetFromId(int32 id) const {
   return GetMainDocument().accessibilityObjectFromID(id);
 }
 
 int32 BlinkAXTreeSource::GetId(blink::WebAXObject node) const {
   return node.axID();
@@ skipping 431 matching lines @@
   WebLocalFrame* main_frame =
       view ? view->mainFrame()->toWebLocalFrame() : NULL;
 
   if (main_frame)
     return main_frame->document();
 
   return WebDocument();
 }
 
 }  // namespace content