Stop rebuilding the task manager list view after every new row added.

chrome/browser/ui/views/task_manager_view.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 "chrome/browser/task_manager/task_manager.h"
 
 #include "app/l10n_util.h"
 #include "app/table_model_observer.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
@@ skipping 163 matching lines @@
 
 void TaskManagerTableModel::OnItemsChanged(int start, int length) {
   if (observer_)
     observer_->OnItemsChanged(start, length);
 }
 
 void TaskManagerTableModel::OnItemsAdded(int start, int length) {
   if (observer_)
     observer_->OnItemsAdded(start, length);
   // There's a bug in the Windows ListView where inserting items with groups
-  // enabled puts them in the wrong position, so we just rebuild the list view
-  // in this case.
-  // (see: http://connect.microsoft.com/VisualStudio/feedback/details/115345/)
-  OnModelChanged();
+  // enabled puts them in the wrong position, so we will need to rebuild the
+  // list view in this case.
+  // (see: http://connect.microsoft.com/VisualStudio/feedback/details/115345/).
+  //
+  // Turns out, forcing a list view rebuild causes http://crbug.com/69391
+  // because items are added to the ListView one-at-a-time when initially
+  // displaying the TaskManager, resulting in many ListView rebuilds. So we are
+  // no longer forcing a rebuild for now because the current UI doesn't use
+  // groups - if we are going to add groups in the upcoming TaskManager UI
+  // revamp, we'll need to re-enable this call to OnModelChanged() and also add
+  // code to avoid doing multiple rebuilds on startup (maybe just generate a
+  // single OnModelChanged() call after the initial population).
+
+  // OnModelChanged();
 }
 
 void TaskManagerTableModel::OnItemsRemoved(int start, int length) {
   if (observer_)
     observer_->OnItemsRemoved(start, length);
 
   // We may need to change the indentation of some items if the topmost item
   // in the group was removed, so update the view.
   OnModelChanged();
 }
@@ skipping 498 matching lines @@
 }  // namespace
 
 namespace browser {
 
 // Declared in browser_dialogs.h so others don't need to depend on our header.
 void ShowTaskManager() {
   TaskManagerView::Show();
 }
 
 }  // namespace browser