FileSystem code cleanup 2nd cut - introduce SandboxedFileSystemOperation

chrome/browser/file_system/browser_file_system_callback_dispatcher.cc

Index: chrome/browser/file_system/browser_file_system_callback_dispatcher.cc
diff --git a/chrome/browser/file_system/browser_file_system_callback_dispatcher.cc b/chrome/browser/file_system/browser_file_system_callback_dispatcher.cc
index b95930f0dfb7ff02b97d401497711c13ed212517..810bf3f8bafe2bb4ab2b51dfcfc4d1d3e9633773 100644
--- a/chrome/browser/file_system/browser_file_system_callback_dispatcher.cc
+++ b/chrome/browser/file_system/browser_file_system_callback_dispatcher.cc
@@ -36,8 +36,11 @@ void BrowserFileSystemCallbackDispatcher::DidReadDirectory(
 }
 
 void BrowserFileSystemCallbackDispatcher::DidOpenFileSystem(
-    const std::string&, const FilePath&) {
-  NOTREACHED();
+    const std::string& name, const FilePath& path) {
+  dispatcher_host_->Send(
+      new ViewMsg_OpenFileSystemRequest_Complete(
+          request_id_, !path.empty(), name, path));
+  dispatcher_host_->RemoveCompletedOperation(request_id_);
 }
 
 void BrowserFileSystemCallbackDispatcher::DidFail(