Helper functions for tracking stale TabContentsDelegate's.

content/browser/tab_contents/tab_contents.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.h"
 
 #include <cmath>
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
@@ skipping 236 matching lines @@
 
   // OnCloseStarted isn't called in unit tests.
   if (!tab_close_start_time_.is_null()) {
     UMA_HISTOGRAM_TIMES("Tab.Close",
         base::TimeTicks::Now() - tab_close_start_time_);
   }
 
   FOR_EACH_OBSERVER(TabContentsObserver, observers_, TabContentsDestroyed());
 
   net::NetworkChangeNotifier::RemoveOnlineStateObserver(this);
+
+  set_delegate(NULL);
+}
+
+// TODO(cbentzel): Either remove the debugging code, or rename to SetDelegate.
+void TabContents::set_delegate(TabContentsDelegate* delegate) {
+  if (delegate == delegate_)
+    return;
+  if (delegate_)
+    delegate_->Detach(this);
+  delegate_ = delegate;
+  if (delegate_)
+    delegate_->Attach(this);
 }
 
 void TabContents::AddObservers() {
   net::NetworkChangeNotifier::AddOnlineStateObserver(this);
 }
 
 bool TabContents::OnMessageReceived(const IPC::Message& message) {
   if (web_ui() && web_ui()->OnMessageReceived(message))
     return true;
 
@@ skipping 1571 matching lines @@
 
 void TabContents::CreateViewAndSetSizeForRVH(RenderViewHost* rvh) {
   RenderWidgetHostView* rwh_view = view()->CreateViewForWidget(rvh);
   rwh_view->SetSize(view()->GetContainerSize());
 }
 
 void TabContents::OnOnlineStateChanged(bool online) {
   render_view_host()->Send(new ViewMsg_NetworkStateChanged(
       render_view_host()->routing_id(), online));
 }