Move MTPDeviceDelegateImplLinux worker classes to its own files.

chrome/browser/media_gallery/linux/mtp_device_operations_utils.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 "chrome/browser/media_gallery/linux/mtp_device_operations_utils.h"
+
+#include "chrome/browser/media_transfer_protocol/media_transfer_protocol_manager.h"
+
+namespace chrome {
+
+// Returns MediaTransferProtocolManager instance on success or NULL on failure.
+MediaTransferProtocolManager* GetMediaTransferProtocolManager() {
+  MediaTransferProtocolManager* mtp_device_mgr =
+      MediaTransferProtocolManager::GetInstance();
+  DCHECK(mtp_device_mgr);
+  return mtp_device_mgr;
+}
+
+}  // namespace chrome