We have a problem in the process on destroying WebContentsImpl because

chrome/browser/ui/views/hung_renderer_view.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 "chrome/browser/ui/views/hung_renderer_view.h"
 
 #include "base/i18n/rtl.h"
 #include "base/memory/scoped_vector.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/favicon/favicon_tab_helper.h"
@@ skipping 137 matching lines @@
     HungPagesTableModel* model, WebContents* tab)
     : content::WebContentsObserver(tab),
       model_(model) {
 }
 
 void HungPagesTableModel::WebContentsObserverImpl::RenderProcessGone(
     base::TerminationStatus status) {
   model_->TabDestroyed(this);
 }
 
-void HungPagesTableModel::WebContentsObserverImpl::WebContentsDestroyed(
-    WebContents* tab) {
+void HungPagesTableModel::WebContentsObserverImpl::WebContentsDestroyed() {
   model_->TabDestroyed(this);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // HungRendererDialogView
 
 // static
 gfx::ImageSkia* HungRendererDialogView::frozen_icon_ = NULL;
 
 // The dimensions of the hung pages list table view, in pixels.
@@ skipping 279 matching lines @@
   HungRendererDialogView* view = HungRendererDialogView::Create(toplevel_view);
   view->ShowForWebContents(contents);
 }
 
 void HideHungRendererDialog(WebContents* contents) {
   if (!logging::DialogsAreSuppressed() && HungRendererDialogView::GetInstance())
     HungRendererDialogView::GetInstance()->EndForWebContents(contents);
 }
 
 }  // namespace chrome