Adds some debugging code in hopes of figuring out why we're

chrome/browser/tabs/tab_strip_model.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/tabs/tab_strip_model.h"
 
 #include <algorithm>
 #include <map>
 
 #include "base/command_line.h"
@@ skipping 191 matching lines @@
   InternalCloseTabs(closing_tabs, CLOSE_NONE);
 }
 
 TabContentsWrapper* TabStripModel::DetachTabContentsAt(int index) {
   if (contents_data_.empty())
     return NULL;
 
   DCHECK(ContainsIndex(index));
 
   TabContentsWrapper* removed_contents = GetContentsAt(index);
-  int next_selected_index = order_controller_->DetermineNewSelectedIndex(index);
+  // TODO(sky): nuke reason and old_data when we figure out what is causing
+  // 34135.
+  volatile int reason = 0;
+  int next_selected_index =
+      order_controller_->DetermineNewSelectedIndex(index, &reason);
+  volatile TabContentsData old_data = *contents_data_.at(index);
   delete contents_data_.at(index);
   contents_data_.erase(contents_data_.begin() + index);
   if (empty())
     closing_all_ = true;
   FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
       TabDetachedAt(removed_contents, index));
   if (empty()) {
     // TabDetachedAt() might unregister observers, so send |TabStripEmtpy()| in
     // a second pass.
     FOR_EACH_OBSERVER(TabStripModelObserver, observers_, TabStripEmpty());
@@ skipping 781 matching lines @@
   FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                     TabMoved(moved_data->contents, index, to_position));
 }
 
 // static
 bool TabStripModel::OpenerMatches(const TabContentsData* data,
                                   const NavigationController* opener,
                                   bool use_group) {
   return data->opener == opener || (use_group && data->group == opener);
 }