Move Sad Tab implementation out of the TabContentsViews.

content/browser/tab_contents/tab_contents_observer.cc

 // 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.
 
 #include "content/browser/tab_contents/tab_contents_observer.h"
 
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/tab_contents/navigation_details.h"
 #include "content/browser/tab_contents/tab_contents.h"
 
 void TabContentsObserver::RenderViewCreated(RenderViewHost* render_view_host) {
 }
 
 void TabContentsObserver::RenderViewDeleted(RenderViewHost* render_view_host) {
 }
 
 void TabContentsObserver::RenderViewReady() {
 }
 
-void TabContentsObserver::RenderViewGone() {
+void TabContentsObserver::RenderViewGone(base::TerminationStatus status) {
 }
 
 void TabContentsObserver::NavigateToPendingEntry(
     const GURL& url,
     NavigationController::ReloadType reload_type) {
 }
 
 void TabContentsObserver::DidNavigateMainFrame(
     const content::LoadCommittedDetails& details,
     const ViewHostMsg_FrameNavigate_Params& params) {
@@ skipping 122 matching lines @@
 }
 
 void TabContentsObserver::TabContentsDestroyed() {
   // Do cleanup so that 'this' can safely be deleted from
   // TabContentsDestroyed.
   tab_contents_->RemoveObserver(this);
   TabContents* tab = tab_contents_;
   tab_contents_ = NULL;
   TabContentsDestroyed(tab);
 }