Add histogram for how tab closing time. Did some cleanup along the way.

chrome/browser/tabs/tab_strip_model.cc

 // Copyright (c) 2006-2008 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 "base/command_line.h"
 #include "base/stl_util-inl.h"
@@ skipping 626 matching lines @@
     for (std::map<RenderProcessHost*, size_t>::iterator iter =
             processes.begin();
         iter != processes.end(); ++iter) {
       iter->first->FastShutdownForPageCount(iter->second);
     }
   }
 
   // We now return to our regularly scheduled shutdown procedure.
   for (size_t i = 0; i < indices.size(); ++i) {
     TabContents* detached_contents = GetContentsAt(indices[i]);
+    detached_contents->OnCloseStarted();
 
     if (!delegate_->CanCloseContentsAt(indices[i]) ||
         delegate_->RunUnloadListenerBeforeClosing(detached_contents)) {
       retval = false;
       continue;
     }
 
     FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
         TabClosingAt(detached_contents, indices[i]));
 
-    if (detached_contents) {

[tony, 2009/10/14 23:20:06]

Maybe we should DCHECK |detached_contents| above?

[jam, 2009/10/14 23:31:11]

I took it out because delegate_->RunUnloadListenerBeforeClosing uses it without
null checking, so if it could have been NULL we'd have seen crashes there.  It
also looks like GetContentsAt has a CHECK there.

-      // Ask the delegate to save an entry for this tab in the historical tab
-      // database if applicable.
-      if (create_historical_tabs)
-        delegate_->CreateHistoricalTab(detached_contents);
+    // Ask the delegate to save an entry for this tab in the historical tab
+    // database if applicable.
+    if (create_historical_tabs)
+      delegate_->CreateHistoricalTab(detached_contents);
 
-      // Deleting the TabContents will call back to us via NotificationObserver
-      // and detach it.
-      delete detached_contents;
-    }
+    // Deleting the TabContents will call back to us via NotificationObserver
+    // and detach it.
+    delete detached_contents;
   }
 
   return retval;
 }
 
 void TabStripModel::MoveTabContentsAtImpl(int index, int to_position,
                                           bool select_after_move,
                                           bool update_pinned_state) {
   DCHECK(ContainsIndex(index));
   if (index == to_position)
@@ skipping 59 matching lines @@
   int index = GetIndexOfTabContents(contents);
   contents_data_.at(index)->opener = &opener->controller();
 }
 
 // static
 bool TabStripModel::OpenerMatches(const TabContentsData* data,
                                   const NavigationController* opener,
                                   bool use_group) {
   return data->opener == opener || (use_group && data->group == opener);
 }