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

chrome/browser/tabs/tab_strip_model_order_controller.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_order_controller.h"
 
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 // TabStripModelOrderController, public:
@@ skipping 46 matching lines @@
   // In other cases, such as Ctrl+T, open at the end of the strip.
   return DetermineInsertionIndexForAppending();
 }
 
 int TabStripModelOrderController::DetermineInsertionIndexForAppending() {
   return (insertion_policy_ == TabStripModel::INSERT_AFTER) ?
       tabstrip_->count() : 0;
 }
 
 int TabStripModelOrderController::DetermineNewSelectedIndex(
-    int removing_index) const {
+    int removing_index, volatile int* reason) const {
   int tab_count = tabstrip_->count();
   DCHECK(removing_index >= 0 && removing_index < tab_count);
   NavigationController* parent_opener =
       tabstrip_->GetOpenerOfTabContentsAt(removing_index);
   // First see if the index being removed has any "child" tabs. If it does, we
   // want to select the first in that child group, not the next tab in the same
   // group of the removed tab.
   NavigationController* removed_controller =
       &tabstrip_->GetTabContentsAt(removing_index)->controller();
+  // The parent opener should never be the same as the controller being removed.
+  CHECK(parent_opener != removed_controller);
   int index = tabstrip_->GetIndexOfNextTabContentsOpenedBy(removed_controller,
                                                            removing_index,
                                                            false);
-  if (index != TabStripModel::kNoTab)
+  if (index != TabStripModel::kNoTab) {
+    *reason = 1;
     return GetValidIndex(index, removing_index);
+  }
 
   if (parent_opener) {
     // If the tab was in a group, shift selection to the next tab in the group.
     int index = tabstrip_->GetIndexOfNextTabContentsOpenedBy(parent_opener,
                                                              removing_index,
                                                              false);
-    if (index != TabStripModel::kNoTab)
+    if (index != TabStripModel::kNoTab) {
+      *reason = 2;
       return GetValidIndex(index, removing_index);
+    }
 
     // If we can't find a subsequent group member, just fall back to the
     // parent_opener itself. Note that we use "group" here since opener is
     // reset by select operations..
     index = tabstrip_->GetIndexOfController(parent_opener);
-    if (index != TabStripModel::kNoTab)
+    if (index != TabStripModel::kNoTab) {
+      *reason = 3;
       return GetValidIndex(index, removing_index);
+    }
   }
 
   // No opener set, fall through to the default handler...
   int selected_index = tabstrip_->selected_index();
-  if (selected_index >= (tab_count - 1))
+  if (selected_index >= (tab_count - 1)) {
+    *reason = 4;
     return selected_index - 1;
+  }
 
+  *reason = 5;
   return selected_index;
 }
 
 void TabStripModelOrderController::TabSelectedAt(
     TabContentsWrapper* old_contents,
     TabContentsWrapper* new_contents,
     int index,
     bool user_gesture) {
   NavigationController* old_opener = NULL;
   if (old_contents) {
@@ skipping 18 matching lines @@
 
 ///////////////////////////////////////////////////////////////////////////////
 // TabStripModelOrderController, private:
 
 int TabStripModelOrderController::GetValidIndex(
     int index, int removing_index) const {
   if (removing_index < index)
     index = std::max(0, index - 1);
   return index;
 }