We have a problem in the process on destroying WebContentsImpl because

chrome/browser/ui/omnibox/omnibox_navigation_observer.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/omnibox/omnibox_navigation_observer.h"
 
 #include "chrome/browser/autocomplete/shortcuts_backend.h"
 #include "chrome/browser/autocomplete/shortcuts_backend_factory.h"
 #include "chrome/browser/infobars/infobar_service.h"
 #include "chrome/browser/intranet_redirect_detector.h"
@@ skipping 90 matching lines @@
 void OmniboxNavigationObserver::NavigationEntryCommitted(
     const content::LoadCommittedDetails& load_details) {
   load_state_ = LOAD_COMMITTED;
   if (ResponseCodeIndicatesSuccess(load_details.http_status_code) &&
       IsValidNavigation(match_.destination_url, load_details.entry->GetURL()))
     OnSuccessfulNavigation();
   if (!fetcher_ || (fetch_state_ != FETCH_NOT_COMPLETE))
     OnAllLoadingFinished();  // deletes |this|!
 }
 
-void OmniboxNavigationObserver::WebContentsDestroyed(
-    content::WebContents* web_contents) {
+void OmniboxNavigationObserver::WebContentsDestroyed() {
   delete this;
 }
 
 void OmniboxNavigationObserver::DidStartNavigationToPendingEntry(
     const GURL& url,
     content::NavigationController::ReloadType reload_type) {
   if (load_state_ == LOAD_NOT_SEEN) {
     load_state_ = LOAD_PENDING;
     if (fetcher_)
       fetcher_->Start();
@@ skipping 18 matching lines @@
     OnAllLoadingFinished();  // deletes |this|!
 }
 
 void OmniboxNavigationObserver::OnAllLoadingFinished() {
   if (fetch_state_ == FETCH_SUCCEEDED) {
     AlternateNavInfoBarDelegate::Create(
         web_contents(), text_, alternate_nav_match_, match_.destination_url);
   }
   delete this;
 }