[ew] Add basic classes.

chrome/browser/chromeos/drive/fileapi/file_system_backend_delegate.h

Index: chrome/browser/chromeos/drive/fileapi/file_system_backend_delegate.h
diff --git a/chrome/browser/chromeos/drive/fileapi/file_system_backend_delegate.h b/chrome/browser/chromeos/drive/fileapi/file_system_backend_delegate.h
index 0d859c97859aec3008e99e7d85eb7b6e748c1db5..c3579667f7d0fbed2e5a53c11316b3d16e3db195 100644
--- a/chrome/browser/chromeos/drive/fileapi/file_system_backend_delegate.h
+++ b/chrome/browser/chromeos/drive/fileapi/file_system_backend_delegate.h
@@ -11,8 +11,16 @@
 
 namespace fileapi {
 class AsyncFileUtil;
+class FileSystemContext;
+class FileSystemURL;
+class FileStreamWriter;
+class WatcherManager;
 }  // namespace fileapi
 
+namespace webkit_blob {
+class FileStreamReader;
+}  // namespace webkit_blob
+
 namespace drive {
 
 // Delegate implementation of the some methods in chromeos::FileSystemBackend
@@ -34,6 +42,8 @@ class FileSystemBackendDelegate : public chromeos::FileSystemBackendDelegate {
       const fileapi::FileSystemURL& url,
       int64 offset,
       fileapi::FileSystemContext* context) OVERRIDE;
+  virtual fileapi::WatcherManager* GetWatcherManager(
+      const fileapi::FileSystemURL& url) OVERRIDE;
 
  private:
   scoped_ptr<fileapi::AsyncFileUtil> async_file_util_;