Browser crashing when closing the WebUI task manager.

chrome/browser/ui/webui/task_manager_handler.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/ui/webui/task_manager_handler.h"
 
 #include <algorithm>
 #include <functional>
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 383 matching lines @@
     rvh->UpdateWebkitPreferences(webkit_prefs);
   } else {
     DCHECK(false);
   }
 
   task_manager_->OpenAboutMemory();
 }
 
 // TaskManagerHandler, private: -----------------------------------------------
 
+bool TaskManagerHandler::is_alive() {
+  return web_ui_->tab_contents()->render_view_host();
+}
+
 void TaskManagerHandler::UpdateResourceGroupTable(int start, int length) {
   if (resource_to_group_table_.size() < static_cast<size_t>(start)) {
     length += start - resource_to_group_table_.size();
     start = resource_to_group_table_.size();
   }
 
   // Makes room to fill group_index at first since inserting vector is too slow.
   std::vector<int>::iterator it = resource_to_group_table_.begin() + start;
   resource_to_group_table_.insert(it, static_cast<size_t>(length), -1);
 
   for (int i = start; i < start + length; i++) {
     const int group_index = model_->GetGroupIndexForResource(i);
     resource_to_group_table_[i] = group_index;
   }
 }
 
 void TaskManagerHandler::OnGroupChanged(const int group_start,
                                         const int group_length) {
   base::FundamentalValue start_value(group_start);
   base::FundamentalValue length_value(group_length);
   base::ListValue tasks_value;
 
   for (int i = 0; i < group_length; ++i)
     tasks_value.Append(CreateTaskGroupValue(model_, group_start + i));
 
-  if (is_enabled_) {
+  if (is_enabled_ && is_alive()) {
     web_ui_->CallJavascriptFunction("taskChanged",
                                     start_value, length_value, tasks_value);
   }
 }
 
 void TaskManagerHandler::OnGroupAdded(const int group_start,
                                       const int group_length) {
   base::FundamentalValue start_value(group_start);
   base::FundamentalValue length_value(group_length);
   base::ListValue tasks_value;
   for (int i = 0; i < group_length; ++i)
     tasks_value.Append(CreateTaskGroupValue(model_, group_start + i));
 
-  if (is_enabled_) {
+  if (is_enabled_ && is_alive()) {
     web_ui_->CallJavascriptFunction("taskAdded",
                                     start_value, length_value, tasks_value);
   }
 }
 
 void TaskManagerHandler::OnGroupRemoved(const int group_start,
                                         const int group_length) {
   base::FundamentalValue start_value(group_start);
   base::FundamentalValue length_value(group_length);
-  if (is_enabled_)
+  if (is_enabled_ && is_alive())
     web_ui_->CallJavascriptFunction("taskRemoved", start_value, length_value);
 }