FileAPI: Factor out getting root URI and FS name parts into each FS backend

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 ff7ebff81082efb8c42805a67425b217813ac3ee..17e708567b5d5b916ce8f02672afb43d849800c2 100644
--- a/webkit/browser/fileapi/test_file_system_backend.cc
+++ b/webkit/browser/fileapi/test_file_system_backend.cc
@@ -104,7 +104,9 @@ void TestFileSystemBackend::OpenFileSystem(
     FileSystemType type,
     OpenFileSystemMode mode,
     const OpenFileSystemCallback& callback) {
-  callback.Run(base::PLATFORM_FILE_OK);
+  callback.Run(GetFileSystemRootURI(origin_url, type),
+               GetFileSystemName(origin_url, type),
+               base::PLATFORM_FILE_OK);
 }
 
 FileSystemFileUtil* TestFileSystemBackend::GetFileUtil(FileSystemType type) {