We have a problem in the process on destroying WebContentsImpl because

chrome/browser/ui/panels/panel_host.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/panels/panel_host.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "chrome/browser/chrome_notification_types.h"
@@ skipping 190 matching lines @@
 void PanelHost::RenderViewCreated(content::RenderViewHost* render_view_host) {
   extensions::WindowController* window = GetExtensionWindowController();
   render_view_host->Send(new ExtensionMsg_UpdateBrowserWindowId(
       render_view_host->GetRoutingID(), window->GetWindowId()));
 }
 
 void PanelHost::RenderProcessGone(base::TerminationStatus status) {
   CloseContents(web_contents_.get());
 }
 
-void PanelHost::WebContentsDestroyed(content::WebContents* web_contents) {
+void PanelHost::WebContentsDestroyed() {
   // Web contents should only be destroyed by us.
   CHECK(!web_contents_.get());
 
   // Close the panel after we return to the message loop (not immediately,
   // otherwise, it may destroy this object before the stack has a chance
   // to cleanly unwind.)
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(&PanelHost::ClosePanel, weak_factory_.GetWeakPtr()));
 }
@@ skipping 38 matching lines @@
 }
 
 void PanelHost::StopLoading() {
   content::RecordAction(UserMetricsAction("Stop"));
   web_contents_->Stop();
 }
 
 void PanelHost::Zoom(content::PageZoom zoom) {
   chrome_page_zoom::Zoom(web_contents_.get(), zoom);
 }