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 199 matching lines @@
   AddObservers();
 }
 
 TabContents::~TabContents() {
   is_being_destroyed_ = true;
 
   // We don't want any notifications while we're running our destructor.
   registrar_.RemoveAll();
 
   // Clear out any JavaScript state.
-  if (delegate_)
+  if (delegate_) {
     delegate_->GetJavaScriptDialogCreator()->ResetJavaScriptState(this);
+    set_delegate(NULL);

[sky, 2011/06/23 18:51:27]

You should do this last. It's possible some of these other methods trigger a
call to the delegate_. In fact it might even be possible for some of the value
objects in TabContents to trigger a call to the delegate_. Not sure.
Seems safest to use Detach at the end.

[cbentzel, 2011/06/23 19:09:57]

Done.

+  }
 
   NotifyDisconnected();
 
   // First cleanly close all child windows.
   // TODO(mpcomplete): handle case if MaybeCloseChildWindows() already asked
   // some of these to close.  CloseWindows is async, so it might get called
   // twice before it runs.
   CloseConstrainedWindows();
 
   // Notify any observer that have a reference on this tab contents.
@@ skipping 384 matching lines @@
                                  WindowOpenDisposition disposition,
                                  const gfx::Rect& initial_pos,
                                  bool user_gesture) {
   if (!delegate_)
     return;
 
   delegate_->AddNewContents(this, new_contents, disposition, initial_pos,
                             user_gesture);
 }
 
+void TabContents::set_delegate(TabContentsDelegate* delegate) {

[sky, 2011/06/23 18:51:27]

Add a TODO about either removing debugging code, or renaming to SetDelegate.

[cbentzel, 2011/06/23 19:09:57]

Done.

+  if (delegate == delegate_)

[cbentzel, 2011/06/23 19:09:57]

Also, compacted vertical whitespace of set_delegate and reordered to appropriate
place in the file.

+    return;
+
+  if (delegate_)
+    delegate_->Detach(this);
+
+  delegate_ = delegate;
+
+  if (delegate_)
+    delegate_->Attach(this);
+}
+
 gfx::NativeView TabContents::GetContentNativeView() const {
   return view_->GetContentNativeView();
 }
 
 gfx::NativeView TabContents::GetNativeView() const {
   return view_->GetNativeView();
 }
 
 void TabContents::GetContainerBounds(gfx::Rect *out) const {
   view_->GetContainerBounds(out);
@@ skipping 1202 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));
 }