Make SupportsUserData sequence-affine instead of thread-affine.

storage/browser/fileapi/file_system_operation_impl.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 "storage/browser/fileapi/file_system_operation_impl.h"
 
 #include <stdint.h>
 
 #include <limits>
 #include <memory>
@@ skipping 366 matching lines @@
 FileSystemOperationImpl::FileSystemOperationImpl(
     const FileSystemURL& url,
     FileSystemContext* file_system_context,
     std::unique_ptr<FileSystemOperationContext> operation_context)
     : file_system_context_(file_system_context),
       operation_context_(std::move(operation_context)),
       async_file_util_(NULL),
       pending_operation_(kOperationNone),
       weak_factory_(this) {
   DCHECK(operation_context_.get());
-  operation_context_->DetachUserDataThread();
+  operation_context_->DetachFromSequence();
   async_file_util_ = file_system_context_->GetAsyncFileUtil(url.type());
   DCHECK(async_file_util_);
 }
 
 void FileSystemOperationImpl::GetUsageAndQuotaThenRunTask(
     const FileSystemURL& url,
     const base::Closure& task,
     const base::Closure& error_callback) {
   storage::QuotaManagerProxy* quota_manager_proxy =
       file_system_context()->quota_manager_proxy();
@@ skipping 196 matching lines @@
 }
 
 bool FileSystemOperationImpl::SetPendingOperationType(OperationType type) {
   if (pending_operation_ != kOperationNone)
     return false;
   pending_operation_ = type;
   return true;
 }
 
 }  // namespace storage