Thread::Stop() must be called before any subclass's destructor completes.

chrome/default_plugin/plugin_install_job_monitor.cc

Index: chrome/default_plugin/plugin_install_job_monitor.cc
diff --git a/chrome/default_plugin/plugin_install_job_monitor.cc b/chrome/default_plugin/plugin_install_job_monitor.cc
index 4e1905751e036297cef1d78c17e7b1571650541a..c9690371317b1db55ca0b0ecc9106bb5023e49bc 100644
--- a/chrome/default_plugin/plugin_install_job_monitor.cc
+++ b/chrome/default_plugin/plugin_install_job_monitor.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -16,6 +16,10 @@ PluginInstallationJobMonitorThread::PluginInstallationJobMonitorThread()
 }
 
 PluginInstallationJobMonitorThread::~PluginInstallationJobMonitorThread() {
+  // The way this class is used, Thread::Stop() has always been called
+  // by the time we reach this point, so we do not need to call it
+  // again.
+  DCHECK(!Thread::IsRunning());
   if (install_job_) {
     ::CloseHandle(install_job_);
     install_job_ = NULL;