Make content_shell handle renderers going away. I've made TabContents call TabContentsView::OnTab...

chrome/browser/ui/tab_contents/tab_contents_wrapper.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_TAB_CONTENTS_TAB_CONTENTS_WRAPPER_H_
 #define CHROME_BROWSER_UI_TAB_CONTENTS_TAB_CONTENTS_WRAPPER_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 201 matching lines @@
   }
 
   WebIntentPickerController* web_intent_picker_controller() {
     return web_intent_picker_controller_.get();
   }
 
   // Overrides -----------------------------------------------------------------
 
   // TabContentsObserver overrides:
   virtual void RenderViewCreated(RenderViewHost* render_view_host) OVERRIDE;
-  virtual void RenderViewGone() OVERRIDE;
   virtual void DidBecomeSelected() OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
   virtual void TabContentsDestroyed(TabContents* tab) OVERRIDE;
 
   // NotificationObserver overrides:
   virtual void Observe(int type,
                        const NotificationSource& source,
                        const NotificationDetails& details) OVERRIDE;
 
  private:
@@ skipping 100 matching lines @@
 
   // The supporting objects need to outlive the TabContents dtor (as they may
   // be called upon during its execution). As a result, this must come last
   // in the list.
   scoped_ptr<TabContents> tab_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(TabContentsWrapper);
 };
 
 #endif  // CHROME_BROWSER_UI_TAB_CONTENTS_TAB_CONTENTS_WRAPPER_H_