Fix up some tests for copy-or-move validator and nearby.

webkit/browser/fileapi/test_file_system_backend.cc

Index: webkit/browser/fileapi/test_file_system_backend.cc
diff --git a/webkit/browser/fileapi/test_file_system_backend.cc b/webkit/browser/fileapi/test_file_system_backend.cc
index 547d6eb4f362db72f1c9dd074f9c681fa935a161..fe01ebfa3df41d8725faf52d820e465afa9d171a 100644
--- a/webkit/browser/fileapi/test_file_system_backend.cc
+++ b/webkit/browser/fileapi/test_file_system_backend.cc
@@ -185,15 +185,14 @@ TestFileSystemBackend::GetCopyOrMoveFileValidatorFactory(
 
 void TestFileSystemBackend::InitializeCopyOrMoveFileValidatorFactory(
     scoped_ptr<CopyOrMoveFileValidatorFactory> factory) {
-  // What purpose is this check serving?
-  if (!require_copy_or_move_validator_) {
-    DCHECK(!factory);
-    return;
-  }
   if (!copy_or_move_file_validator_factory_)
     copy_or_move_file_validator_factory_ = factory.Pass();
 }
 
+void TestFileSystemBackend::ResetCopyOrMoveFileValidatorFactory() {
+  copy_or_move_file_validator_factory_.reset();
+}
+
 FileSystemOperation* TestFileSystemBackend::CreateFileSystemOperation(
     const FileSystemURL& url,
     FileSystemContext* context,