Move chrome/browser/chromeos/drive/file_system.cc (+deps) into components/drive.

chrome/browser/chromeos/drive/remove_stale_cache_files.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/chromeos/drive/remove_stale_cache_files.h"
-
-#include "base/logging.h"
-#include "components/drive/drive.pb.h"
-#include "components/drive/file_cache.h"
-#include "components/drive/resource_metadata.h"
-
-namespace drive {
-namespace internal {
-
-void RemoveStaleCacheFiles(FileCache* cache,
-                           ResourceMetadata* resource_metadata) {
-  scoped_ptr<ResourceMetadata::Iterator> it = resource_metadata->GetIterator();
-  for (; !it->IsAtEnd(); it->Advance()) {
-    const ResourceEntry& entry = it->GetValue();
-    const FileCacheEntry& cache_state =
-        entry.file_specific_info().cache_state();
-    // Stale = not dirty but the MD5 does not match.
-    if (!cache_state.is_dirty() &&
-        cache_state.md5() != entry.file_specific_info().md5()) {
-      FileError error = cache->Remove(it->GetID());
-      LOG_IF(WARNING, error != FILE_ERROR_OK)
-          << "Failed to remove a stale cache file. resource_id: "
-          << it->GetID();
-    }
-  }
-}
-
-}  // namespace internal
-}  // namespace drive