Revert r286729

content/child/process_background_message_filter.h

Index: content/child/process_background_message_filter.h
diff --git a/content/child/process_background_message_filter.h b/content/child/process_background_message_filter.h
deleted file mode 100644
index bc1e2161240cecea30b79a53654a0e60ed9eb917..0000000000000000000000000000000000000000
--- a/content/child/process_background_message_filter.h
+++ /dev/null
@@ -1,40 +0,0 @@
-// 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.
-
-#ifndef CONTENT_CHILD_PROCESS_BACKGROUND_MESSAGE_FILTER_H_
-#define CONTENT_CHILD_PROCESS_BACKGROUND_MESSAGE_FILTER_H_
-
-#include "base/memory/ref_counted.h"
-#include "base/single_thread_task_runner.h"
-#include "base/threading/thread_checker.h"
-#include "ipc/message_filter.h"
-
-namespace base {
-class SingleThreadTaskRunner;
-}
-
-namespace content {
-
-// Receives process background messages from the browser process and processes
-// them on the IO thread.
-class ProcessBackgroundMessageFilter : public IPC::MessageFilter {
- public:
-  ProcessBackgroundMessageFilter();
-
-  // IPC::MessageFilter
-  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
-
- private:
-  virtual ~ProcessBackgroundMessageFilter();
-
-  void OnProcessBackgrounded(bool background);
-  void SetTimerSlack(bool background);
-
-  base::ThreadChecker thread_checker_;
-  scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
-};
-
-}  // namespace content
-
-#endif  // CONTENT_CHILD_PROCESS_BACKGROUND_MESSAGE_FILTER_H_