Move media library AutoTaskRunner to base and rename ScopedTaskRunner.

base/task.cc

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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/task.h"
 
 Task::Task() {
 }
 
 Task::~Task() {
 }
 
 CancelableTask::CancelableTask() {
 }
 
 CancelableTask::~CancelableTask() {
 }
+
+namespace base {
+
+ScopedTaskRunner::ScopedTaskRunner(Task* task) : task_(task) {
+}
+
+ScopedTaskRunner::~ScopedTaskRunner() {
+  if (task_) {
+    task_->Run();
+    delete task_;
+  }
+}
+
+Task* ScopedTaskRunner::Release() {
+  Task* tmp = task_;
+  task_ = NULL;
+  return tmp;
+}
+
+}  // namespace base