Add thread checker to FileSystemOperationContext to allow setters called only on initialization thr…

webkit/fileapi/local_file_system_operation.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 "webkit/fileapi/local_file_system_operation.h"
 
 #include "base/bind.h"
 #include "base/single_thread_task_runner.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
@@ skipping 35 matching lines @@
       peer_handle_(base::kNullProcessHandle),
       pending_operation_(kOperationNone),
       weak_factory_(this) {
   DCHECK(operation_context_.get());
   operation_context_->DetachUserDataThread();
 }
 
 LocalFileSystemOperation::~LocalFileSystemOperation() {
   if (!operation_context())
     return;
-  operation_context()->DetachUserDataThread();
   if (write_target_url_.is_valid()) {
     operation_context()->update_observers()->Notify(
         &FileUpdateObserver::OnEndUpdate, MakeTuple(write_target_url_));
   }
 }
 
 void LocalFileSystemOperation::CreateFile(const FileSystemURL& url,
                                           bool exclusive,
                                           const StatusCallback& callback) {
   DCHECK(SetPendingOperationType(kOperationCreateFile));
@@ skipping 805 matching lines @@
 }
 
 bool LocalFileSystemOperation::SetPendingOperationType(OperationType type) {
   if (pending_operation_ != kOperationNone)
     return false;
   pending_operation_ = type;
   return true;
 }
 
 }  // namespace fileapi