Update TaskTraits in dom_storage_context_wrapper.cc.

content/browser/dom_storage/dom_storage_context_wrapper.cc

 // Copyright 2013 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 "content/browser/dom_storage/dom_storage_context_wrapper.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 264 matching lines @@
   scoped_refptr<base::SequencedTaskRunner> primary_sequence;
   scoped_refptr<base::SequencedTaskRunner> commit_sequence;
   if (GetContentClient()->browser()->ShouldRedirectDOMStorageTaskRunner()) {
     // TaskPriority::USER_BLOCKING as an experiment because this is currently
     // believed to be blocking synchronous IPCs from the renderers:
     // http://crbug.com/665588 (yes we want to fix that bug, but are taking it
     // as an opportunity to experiment with the scheduler).
     base::TaskTraits dom_storage_traits =
         base::TaskTraits()
             .WithShutdownBehavior(base::TaskShutdownBehavior::BLOCK_SHUTDOWN)
-            .WithFileIO()
+            .MayBlock()
             .WithPriority(base::TaskPriority::USER_BLOCKING);
     primary_sequence =
         base::CreateSequencedTaskRunnerWithTraits(dom_storage_traits);
     commit_sequence =
         base::CreateSequencedTaskRunnerWithTraits(dom_storage_traits);
   } else {
     base::SequencedWorkerPool* worker_pool = BrowserThread::GetBlockingPool();
     primary_sequence = worker_pool->GetSequencedTaskRunner(
         worker_pool->GetNamedSequenceToken("dom_storage_primary"));
     commit_sequence = worker_pool->GetSequencedTaskRunner(
@@ skipping 158 matching lines @@
 }
 
 void DOMStorageContextWrapper::PurgeMemory(DOMStorageContextImpl::PurgeOption
     purge_option) {
   context_->task_runner()->PostTask(
       FROM_HERE,
       base::Bind(&DOMStorageContextImpl::PurgeMemory, context_, purge_option));
 }
 
 }  // namespace content