Always delete media galleries FilePathWatchers on the FILE thread.

chrome/browser/media_galleries/fileapi/picasa_data_provider.h

 // Copyright 2013 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 CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_PICASA_DATA_PROVIDER_H_
 #define CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_PICASA_DATA_PROVIDER_H_
 
 #include <map>
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/files/file_path_watcher.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
+#include "chrome/browser/media_galleries/fileapi/file_path_watcher_util.h"
 #include "chrome/common/media_galleries/picasa_types.h"
 
 namespace picasa {
 
 class SafePicasaAlbumTableReader;
 class SafePicasaAlbumsIndexer;
 
 // Created and owned by ImportedMediaGalleryRegistryTaskRunnerValues
 class PicasaDataProvider {
  public:
@@ skipping 29 matching lines @@
     INVALID_DATA_STATE,
     LIST_OF_ALBUMS_AND_FOLDERS_FRESH_STATE,
     ALBUMS_IMAGES_FRESH_STATE
   };
 
   friend class PicasaFileUtilTest;
   friend class TestPicasaDataProvider;
 
   // Called when the FilePathWatcher for Picasa's temp directory has started.
   virtual void OnTempDirWatchStarted(
-      std::unique_ptr<base::FilePathWatcher> temp_dir_watcher);
+      MediaFilePathWatcherUniquePtr temp_dir_watcher);
 
   // Called when Picasa's temp directory has changed. Virtual for testing.
   virtual void OnTempDirChanged(const base::FilePath& temp_dir_path,
                                 bool error);
 
   // Kicks off utility processes needed to fulfill any pending callbacks.
   void DoRefreshIfNecessary();
 
   void OnAlbumTableReaderDone(scoped_refptr<SafePicasaAlbumTableReader> reader,
                               bool parse_success,
@@ skipping 21 matching lines @@
   std::vector<ReadyCallback> albums_index_ready_callbacks_;
 
   // Stores the "live" in-flight utility processes. Callbacks from other
   // (older) utility processes are stale and ignored. Only one of these at a
   // time should be non-NULL.
   scoped_refptr<SafePicasaAlbumTableReader> album_table_reader_;
   scoped_refptr<SafePicasaAlbumsIndexer> albums_indexer_;
 
   // We watch the temp dir, as we can't detect database file modifications on
   // Mac, but we are able to detect creation and deletion of temporary files.
-  std::unique_ptr<base::FilePathWatcher> temp_dir_watcher_;
+  MediaFilePathWatcherUniquePtr temp_dir_watcher_;
 
   base::WeakPtrFactory<PicasaDataProvider> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PicasaDataProvider);
 };
 
 }  // namespace picasa
 
 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_PICASA_DATA_PROVIDER_H_