SyncFS: Introduce SyncFileSystemBackend

webkit/browser/fileapi/sandbox_file_system_backend.h

Index: webkit/browser/fileapi/sandbox_file_system_backend.h
diff --git a/webkit/browser/fileapi/sandbox_file_system_backend.h b/webkit/browser/fileapi/sandbox_file_system_backend.h
index 5ac590f6bc4a9316a0358bd9de870d757346a0ab..19d9004e789a42cb062f83888b6e439902ffee7c 100644
--- a/webkit/browser/fileapi/sandbox_file_system_backend.h
+++ b/webkit/browser/fileapi/sandbox_file_system_backend.h
@@ -68,6 +68,7 @@ class WEBKIT_STORAGE_BROWSER_EXPORT SandboxFileSystemBackend
 
   SandboxFileSystemBackend(
       SandboxContext* sandbox_context,
+      base::SequencedTaskRunner* file_task_runner,
       const FileSystemOptions& file_system_options);
   virtual ~SandboxFileSystemBackend();
 
@@ -79,8 +80,12 @@ class WEBKIT_STORAGE_BROWSER_EXPORT SandboxFileSystemBackend
       OpenFileSystemMode mode,
       FileSystemContext* context,
       const InitializeFileSystemCallback& callback) OVERRIDE;
-  virtual FileSystemFileUtil* GetFileUtil(FileSystemType type) OVERRIDE;
-  virtual AsyncFileUtil* GetAsyncFileUtil(FileSystemType type) OVERRIDE;
+  virtual FileSystemFileUtil* GetFileUtil(
+      FileSystemType type,
+      const FileSystemContext* context) OVERRIDE;
+  virtual AsyncFileUtil* GetAsyncFileUtil(
+      FileSystemType type,
+      const FileSystemContext* context) OVERRIDE;
   virtual CopyOrMoveFileValidatorFactory* GetCopyOrMoveFileValidatorFactory(
       FileSystemType type,
       base::PlatformFileError* error_code) OVERRIDE;
@@ -166,6 +171,21 @@ class WEBKIT_STORAGE_BROWSER_EXPORT SandboxFileSystemBackend
     enable_temporary_file_system_in_incognito_ = enable;
   }
 
+ protected:
+  SandboxContext* sandbox_context_;  // Not owned.
+
+  scoped_refptr<base::SequencedTaskRunner> file_task_runner_;
+
+  // Observers.
+  UpdateObserverList update_observers_;
+  ChangeObserverList change_observers_;
+  AccessObserverList access_observers_;
+
+  // Indicates if the usage tracking for FileSystem is enabled or not.
+  // The usage tracking is enabled by default and can be disabled by
+  // a command-line switch (--disable-file-system-usage-tracking).
+  bool enable_usage_tracking_;
+
  private:
   friend class SandboxQuotaObserver;
   friend class SandboxFileSystemTestHelper;
@@ -201,32 +221,16 @@ class WEBKIT_STORAGE_BROWSER_EXPORT SandboxFileSystemBackend
                          const GURL& origin,
                          FileSystemType type);
 
-  SandboxContext* sandbox_context_;  // Not owned.
-
   FileSystemOptions file_system_options_;
   bool enable_temporary_file_system_in_incognito_;
 
   // Acccessed only on the file thread.
   std::set<GURL> visited_origins_;
 
-  // Observers.
-  UpdateObserverList update_observers_;
-  ChangeObserverList change_observers_;
-  AccessObserverList access_observers_;
-
-  // Observers for syncable file systems.
-  UpdateObserverList syncable_update_observers_;
-  ChangeObserverList syncable_change_observers_;
-
   base::Time next_release_time_for_open_filesystem_stat_;
 
   std::set<std::pair<GURL, FileSystemType> > sticky_dirty_origins_;
 
-  // Indicates if the usage tracking for FileSystem is enabled or not.
-  // The usage tracking is enabled by default and can be disabled by
-  // a command-line switch (--disable-file-system-usage-tracking).
-  bool enable_usage_tracking_;
-
   base::WeakPtrFactory<SandboxFileSystemBackend> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SandboxFileSystemBackend);
@@ -234,4 +238,4 @@ class WEBKIT_STORAGE_BROWSER_EXPORT SandboxFileSystemBackend
 
 }  // namespace fileapi
 
-#endif  // WEBKIT_BROWSER_FILEAPI_SANDBOX_FILE_SYSTEM_BACKEND_H_
+#endif  /// WEBKIT_BROWSER_FILEAPI_SANDBOX_FILE_SYSTEM_BACKEND_H_