Move EnumerateModulesModel work to the blocking pool.

chrome/browser/win/enumerate_modules_model.cc

 // Copyright (c) 2012 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/win/enumerate_modules_model.h"
 
 #include <softpub.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <tlhelp32.h>
@@ skipping 358 matching lines @@
 }
 
 ModuleEnumerator::~ModuleEnumerator() {
 }
 
 void ModuleEnumerator::ScanNow(ModulesVector* list) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   enumerated_modules_ = list;
 
   // This object can't be reaped until it has finished scanning, so its safe
-  // to post a raw pointer to another thread.
-  BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
-                          base::Bind(&ModuleEnumerator::ScanImpl,
-                                     base::Unretained(this)));
+  // to post a raw pointer to another thread. It will simply be leaked if the
+  // scanning has not been finished before shutdown.
+  BrowserThread::GetBlockingPool()->PostWorkerTaskWithShutdownBehavior(
+      FROM_HERE,
+      base::Bind(&ModuleEnumerator::ScanImpl,
+                 base::Unretained(this)),
+      base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN);
 }
 
 void ModuleEnumerator::ScanImpl() {
   base::TimeTicks start_time = base::TimeTicks::Now();
 
   enumerated_modules_->clear();
 
   // Make sure the path mapping vector is setup so we can collapse paths.
   PreparePathMappings();
 
@@ skipping 465 matching lines @@
   module_enumerator_.reset();
 
   UMA_HISTOGRAM_COUNTS_100("Conflicts.SuspectedBadModules",
                            suspected_bad_modules_detected_);
   UMA_HISTOGRAM_COUNTS_100("Conflicts.ConfirmedBadModules",
                            confirmed_bad_modules_detected_);
 
   // Forward the callback to any registered observers.
   FOR_EACH_OBSERVER(Observer, observers_, OnScanCompleted());
 }