Make TabContents own its infobar delegates....

chrome/browser/ui/views/infobars/translate_message_infobar.cc

 // Copyright (c) 2010 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 "chrome/browser/views/infobars/translate_message_infobar.h"
 
 #include "chrome/browser/translate/translate_infobar_delegate.h"
 #include "chrome/browser/views/infobars/infobar_text_button.h"
 #include "views/controls/image_view.h"
 
@@ skipping 31 matching lines @@
   if (button_) {
     button_->SetBounds(label_->bounds().right() +
                           InfoBar::kButtonInLabelSpacing,
                        InfoBar::OffsetY(this, button_pref_size),
                        button_pref_size.width(), button_pref_size.height());
   }
 }
 
 void TranslateMessageInfoBar::ButtonPressed(views::Button* sender,
                                             const views::Event& event) {
-  if (sender == button_) {
+  if (delegate() && (sender == button_)) {
     GetDelegate()->MessageInfoBarButtonPressed();
     return;
   }
   TranslateInfoBarBase::ButtonPressed(sender, event);
 }