Base: Make FileProxy automaticaly close the file on a worker thread.

base/files/file_proxy.cc

 // Copyright 2014 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 "base/files/file_proxy.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/file_util.h"
 #include "base/files/file.h"
 #include "base/location.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/task_runner.h"
 #include "base/task_runner_util.h"
 
+namespace {
+
+void FileDeleter(base::File file) {
+}
+
+}  // namespace
+
 namespace base {
 
 class FileHelper {
  public:
    FileHelper(FileProxy* proxy, File file)
       : file_(file.Pass()),
-        proxy_(AsWeakPtr(proxy)),
-        error_(File::FILE_ERROR_FAILED) {
+        error_(File::FILE_ERROR_FAILED),
+        task_runner_(proxy->task_runner()),
+        proxy_(AsWeakPtr(proxy)) {
    }
 
    void PassFile() {
      if (proxy_)
        proxy_->SetFile(file_.Pass());
+     else if (file_.IsValid())
+       task_runner_->PostTask(FROM_HERE, Bind(&FileDeleter, Passed(&file_)));
    }
 
  protected:
   File file_;
-  WeakPtr<FileProxy> proxy_;
   File::Error error_;
 
  private:
+  scoped_refptr<TaskRunner> task_runner_;
+  WeakPtr<FileProxy> proxy_;
   DISALLOW_COPY_AND_ASSIGN(FileHelper);
 };
 
 namespace {
 
 class GenericFileHelper : public FileHelper {
  public:
   GenericFileHelper(FileProxy* proxy, File file)
       : FileHelper(proxy, file.Pass()) {
   }
@@ skipping 165 matching lines @@
 
  private:
   scoped_ptr<char[]> buffer_;
   int bytes_to_write_;
   int bytes_written_;
   DISALLOW_COPY_AND_ASSIGN(WriteHelper);
 };
 
 }  // namespace
 
-FileProxy::FileProxy() : task_runner_(NULL) {
-}
-
 FileProxy::FileProxy(TaskRunner* task_runner) : task_runner_(task_runner) {
 }
 
 FileProxy::~FileProxy() {
+  if (file_.IsValid())
+    task_runner_->PostTask(FROM_HERE, Bind(&FileDeleter, Passed(&file_)));
 }
 
 bool FileProxy::CreateOrOpen(const FilePath& file_path,
                              uint32 file_flags,
                              const StatusCallback& callback) {
   DCHECK(!file_.IsValid());
   CreateOrOpenHelper* helper = new CreateOrOpenHelper(this, File());
   return task_runner_->PostTaskAndReply(
       FROM_HERE,
       Bind(&CreateOrOpenHelper::RunWork, Unretained(helper), file_path,
@@ skipping 97 matching lines @@
       Bind(&GenericFileHelper::Flush, Unretained(helper)),
       Bind(&GenericFileHelper::Reply, Owned(helper), callback));
 }
 
 void FileProxy::SetFile(File file) {
   DCHECK(!file_.IsValid());
   file_ = file.Pass();
 }
 
 }  // namespace base