[ew] Add basic classes.

chrome/browser/media_galleries/fileapi/media_file_system_backend.cc

Index: chrome/browser/media_galleries/fileapi/media_file_system_backend.cc
diff --git a/chrome/browser/media_galleries/fileapi/media_file_system_backend.cc b/chrome/browser/media_galleries/fileapi/media_file_system_backend.cc
index 866f1ef72ddadcdd6ef4bec10e7b60ea7063c4a1..fbbb1665729da063bd42730a5ee7c5f890004bcd 100644
--- a/chrome/browser/media_galleries/fileapi/media_file_system_backend.cc
+++ b/chrome/browser/media_galleries/fileapi/media_file_system_backend.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/media_galleries/fileapi/media_file_system_backend.h"
 
 #include <string>
+#include <vector>
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
@@ -270,6 +271,11 @@ fileapi::AsyncFileUtil* MediaFileSystemBackend::GetAsyncFileUtil(
   return NULL;
 }
 
+fileapi::WatcherManager* MediaFileSystemBackend::GetWatcherManager(
+    fileapi::FileSystemType type) {
+  return NULL;
+}
+
 fileapi::CopyOrMoveFileValidatorFactory*
 MediaFileSystemBackend::GetCopyOrMoveFileValidatorFactory(
     fileapi::FileSystemType type, base::File::Error* error_code) {