Add an option to specify requested fields for fetching metadata.

chrome/browser/extensions/api/file_system/file_system_api.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/api/file_system/file_system_api.h"
 
 #include <set>
 #include <vector>
 
 #include "apps/saved_files_service.h"
@@ skipping 1131 matching lines @@
         content::BrowserContext::GetStoragePartitionForSite(GetProfile(), site)
             ->GetFileSystemContext();
     const storage::FileSystemURL url = context->CreateCrackedFileSystemURL(
         site,
         storage::kFileSystemTypeIsolated,
         IsolatedContext::GetInstance()
             ->CreateVirtualRootPath(filesystem_id)
             .Append(base::FilePath::FromUTF8Unsafe(filesystem_path)));
 
     content::BrowserThread::PostTask(
-        content::BrowserThread::IO,
-        FROM_HERE,
+        content::BrowserThread::IO, FROM_HERE,
         base::Bind(
             base::IgnoreResult(
                 &storage::FileSystemOperationRunner::GetMetadata),
-            context->operation_runner()->AsWeakPtr(),
-            url,
+            context->operation_runner()->AsWeakPtr(), url,
+            storage::FileSystemOperation::GET_METADATA_FIELD_IS_DIRECTORY,
             base::Bind(
                 &PassFileInfoToUIThread,
                 base::Bind(&FileSystemRetainEntryFunction::RetainFileEntry,
-                           this,
-                           entry_id,
-                           path))));
+                           this, entry_id, path))));
     return true;
   }
 
   saved_files_service->EnqueueFileEntry(extension_->id(), entry_id);
   SendResponse(true);
   return true;
 }
 
 void FileSystemRetainEntryFunction::RetainFileEntry(
     const std::string& entry_id,
@@ skipping 265 matching lines @@
   std::vector<linked_ptr<Volume>> result_volume_list;
   FillVolumeList(chrome_details_.GetProfile(), &result_volume_list);
 
   return RespondNow(
       ArgumentList(api::file_system::GetVolumeList::Results::Create(
                        result_volume_list).Pass()));
 }
 #endif
 
 }  // namespace extensions