[Extensions] Isolate ExtensionFunction results_ and error_

chrome/browser/chromeos/extensions/file_system_provider/provider_function.cc

 // Copyright 2014 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 <utility>
 
 #include "chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h"
 #include "chrome/browser/chromeos/file_system_provider/provided_file_system_interface.h"
 #include "chrome/browser/chromeos/file_system_provider/request_manager.h"
 #include "chrome/browser/chromeos/file_system_provider/request_value.h"
@@ skipping 145 matching lines @@
     return false;
 
   return RunWhenValid();
 }
 
 bool FileSystemProviderInternalFunction::Parse() {
   std::string file_system_id;
 
   if (!args_->GetString(0, &file_system_id) ||
       !args_->GetInteger(1, &request_id_)) {
-    bad_message_ = true;
+    set_bad_message(true);
     return false;
   }
 
   Service* service = Service::Get(GetProfile());
   if (!service) {
     return false;
   }
 
   ProvidedFileSystemInterface* file_system =
       service->GetProvidedFileSystem(extension_id(), file_system_id);
   if (!file_system) {
     SetError(FileErrorToString(base::File::FILE_ERROR_NOT_FOUND));
     return false;
   }
 
   request_manager_ = file_system->GetRequestManager();
   return true;
 }
 
 }  // namespace extensions