OpenItem now posts its task with CONTINUE_ON_SHUTDOWN semantic.

chrome/browser/platform_util.cc

 // Copyright 2015 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/platform_util.h"
 
 #include "base/files/file.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"
+#include "chrome/browser/browser_hangs_experiment.h"
 #include "chrome/browser/platform_util_internal.h"
 #include "content/public/browser/browser_thread.h"
 
 using content::BrowserThread;
 
 namespace platform_util {
 
 namespace {
 
 bool shell_operations_allowed = true;
@@ skipping 11 matching lines @@
   if (base::DirectoryExists(path) != (type == OPEN_FOLDER)) {
     if (!callback.is_null())
       BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
                               base::Bind(callback, OPEN_FAILED_INVALID_TYPE));
     return;
   }
 
   if (shell_operations_allowed)
     internal::PlatformOpenVerifiedItem(path, type);
   if (!callback.is_null())
     BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,

[manzagop (departed), 2016/04/25 14:28:26]

Is it an issue to post a task from a continue on shutdown task?

[Patrick Monette, 2016/04/28 20:22:09]

Lets ask gab@!

[gab, 2016/04/28 22:36:25]

It shouldn't be:

 - for BrowserThread MessageLoops either the loop is up or it's not (if it's not
PostTask will simply return false and the task will never run; if it is the task
will be posted and will most likely block the join of that thread).

 - for the SequencedWorkerPool I'm not sure (but I'd assume PostTask also
returns false, unless shutdown isn't complete and the task is BLOCK_SHUTDOWN but
that'd be reeeaaaaalllly weird to do!).

                             base::Bind(callback, OPEN_SUCCEEDED));
 }
 
 }  // namespace
 
 namespace internal {
 
 void DisableShellOperationsForTesting() {
   shell_operations_allowed = false;
 }
 
 }  // namespace internal
 
 void OpenItem(Profile* profile,
               const base::FilePath& full_path,
               OpenItemType item_type,
               const OpenOperationCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  BrowserThread::PostBlockingPoolTask(
+  base::SequencedWorkerPool::WorkerShutdown shutdown_mode =
+      IsBrowserHangsExperimentEnabled()
+          ? base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN
+          : base::SequencedWorkerPool::SKIP_ON_SHUTDOWN;
+  BrowserThread::GetBlockingPool()->PostWorkerTaskWithShutdownBehavior(
       FROM_HERE, base::Bind(&VerifyAndOpenItemOnBlockingThread, full_path,
-                            item_type, callback));
+                            item_type, callback),
+      shutdown_mode);
 }
 
 }  // namespace platform_util