Add update observer to file_system_operation_impl_unittest for

content/public/test/sandbox_file_system_test_helper.cc

 // 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.
 
 #include "content/public/test/sandbox_file_system_test_helper.h"
 
 #include "base/files/file_util.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/run_loop.h"
 #include "content/public/test/mock_special_storage_policy.h"
@@ skipping 118 matching lines @@
       *file_system_context_->GetUpdateObservers(type_));
   return context;
 }
 
 void SandboxFileSystemTestHelper::AddFileChangeObserver(
     storage::FileChangeObserver* observer) {
   file_system_context_->sandbox_delegate()->AddFileChangeObserver(
       type_, observer, NULL);
 }
 
+void SandboxFileSystemTestHelper::AddFileUpdateObserver(
+    storage::FileUpdateObserver* observer) {
+  file_system_context_->sandbox_delegate()->AddFileUpdateObserver(
+      type_, observer, NULL);
+}
+
 storage::FileSystemUsageCache* SandboxFileSystemTestHelper::usage_cache() {
   return file_system_context()->sandbox_delegate()->usage_cache();
 }
 
 void SandboxFileSystemTestHelper::SetUpFileSystem() {
   DCHECK(file_system_context_.get());
   DCHECK(file_system_context_->sandbox_backend()->CanHandleType(type_));
 
   file_util_ = file_system_context_->sandbox_delegate()->sync_file_util();
   DCHECK(file_util_);
 
   // Prepare the origin's root directory.
   file_system_context_->sandbox_delegate()->
       GetBaseDirectoryForOriginAndType(origin_, type_, true /* create */);
 
   // Initialize the usage cache file.
   base::FilePath usage_cache_path = GetUsageCachePath();
   if (!usage_cache_path.empty())
     usage_cache()->UpdateUsage(usage_cache_path, 0);
 }
 
 }  // namespace content