Fix a stack overflow crash in the accessibility code in the renderer. The crash occurs in the

content/renderer/renderer_accessibility.cc

 // Copyright (c) 2011 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 "base/command_line.h"
 #include "content/common/view_messages.h"
 #include "content/public/common/content_switches.h"
 #include "content/renderer/render_view_impl.h"
 #include "content/renderer/renderer_accessibility.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebAccessibilityObject.h"
@@ skipping 145 matching lines @@
     const WebAccessibilityObject& obj,
     WebAccessibilityNotification notification) {
   if (!WebAccessibilityObject::accessibilityEnabled())
     return;
 
   const WebDocument& document = GetMainDocument();
   if (document.isNull())
     return;
 
   gfx::Size scroll_offset = document.frame()->scrollOffset();
-  if (scroll_offset != last_scroll_offset_) {
+  if (scroll_offset != last_scroll_offset_ &&
+      notification != WebKit::WebAccessibilityNotificationLayoutComplete) {
     // Make sure the browser is always aware of the scroll position of
     // the root document element by posting a generic notification that
     // 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;
     PostAccessibilityNotification(

[David Tseng, 2011/12/15 02:03:59]

I think we should add the exclusion here as the previous line's assignment
should happen regardless.

if (notification != WebKit::WebAccessibilityNotificationLayoutComplete) { 
  Post...

[ananta, 2011/12/15 02:09:56]

Done.

         document.accessibilityObject(),
         WebKit::WebAccessibilityNotificationLayoutComplete);
   }
 
   // Add the accessibility object to our cache and ensure it's valid.
   Notification acc_notification;
   acc_notification.id = obj.axID();
   acc_notification.type = notification;
 
   ViewHostMsg_AccEvent::Value temp;
@@ skipping 328 matching lines @@
 
 WebDocument RendererAccessibility::GetMainDocument() {
   WebView* view = render_view()->GetWebView();
   WebFrame* main_frame = view ? view->mainFrame() : NULL;
 
   if (main_frame)
     return main_frame->document();
   else
     return WebDocument();
 }