We have a problem in the process on destroying WebContentsImpl because

content/browser/web_contents/web_contents_impl.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 "content/browser/web_contents/web_contents_impl.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 271 matching lines @@
 // WebContentsImpl::DestructionObserver ----------------------------------------
 
 class WebContentsImpl::DestructionObserver : public WebContentsObserver {
  public:
   DestructionObserver(WebContentsImpl* owner, WebContents* watched_contents)
       : WebContentsObserver(watched_contents),
         owner_(owner) {
   }
 
   // WebContentsObserver:
-  virtual void WebContentsDestroyed(WebContents* web_contents) OVERRIDE {
-    owner_->OnWebContentsDestroyed(static_cast<WebContentsImpl*>(web_contents));
+  virtual void WebContentsDestroyed() OVERRIDE {
+    owner_->OnWebContentsDestroyed(
+        static_cast<WebContentsImpl*>(web_contents()));
   }
 
  private:
   WebContentsImpl* owner_;
 
   DISALLOW_COPY_AND_ASSIGN(DestructionObserver);
 };
 
 WebContentsImpl::ColorChooserInfo::ColorChooserInfo(int render_process_id,
                                                     int render_frame_id,
@@ skipping 108 matching lines @@
   }
 
   ForEachFrame(run_render_frame_deleted_callback);
 
   FOR_EACH_OBSERVER(WebContentsObserver,
                     observers_,
                     RenderViewDeleted(GetRenderManager()->current_host()));
 
   FOR_EACH_OBSERVER(WebContentsObserver,
                     observers_,
-                    WebContentsImplDestroyed());
+                    WebContentsDestroyed());
+
+  FOR_EACH_OBSERVER(WebContentsObserver,
+                    observers_,
+                    WebContentsDestroyedPrivate());
 
   SetDelegate(NULL);
 
   STLDeleteContainerPairSecondPointers(destruction_observers_.begin(),
                                        destruction_observers_.end());
 }
 
 WebContentsImpl* WebContentsImpl::CreateWithOpener(
     const WebContents::CreateParams& params,
     WebContentsImpl* opener) {
@@ skipping 3491 matching lines @@
 
 void WebContentsImpl::OnPreferredSizeChanged(const gfx::Size& old_size) {
   if (!delegate_)
     return;
   const gfx::Size new_size = GetPreferredSize();
   if (new_size != old_size)
     delegate_->UpdatePreferredSize(this, new_size);
 }
 
 }  // namespace content