[Privet Filesystem] Fix null dereference

chrome/browser/local_discovery/storage/privet_filesystem_operations.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 "chrome/browser/local_discovery/storage/privet_filesystem_operations.h"
 
 #include "chrome/browser/local_discovery/storage/privet_filesystem_constants.h"
 
 namespace local_discovery {
 
@@ skipping 131 matching lines @@
       base::Bind(&PrivetFileSystemListOperation::OnStorageListResult,
                  base::Unretained(this)));
     list_operation_->Start();
 }
 
 void PrivetFileSystemListOperation::OnStorageListResult(
     const base::DictionaryValue* value) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   list_operation_.reset();
 
-  attribute_cache_->AddFileInfoFromJSON(full_path_, value);
-
-  fileapi::AsyncFileUtil::EntryList entry_list;
-
   if (!value) {
     SignalError();
     return;
   }
 
+  attribute_cache_->AddFileInfoFromJSON(full_path_, value);
+
+  fileapi::AsyncFileUtil::EntryList entry_list;
+
   const base::ListValue* entries;
   if (!value->GetList(kPrivetListEntries, &entries)) {
     SignalError();
     return;
   }
 
   for (size_t i = 0; i < entries->GetSize(); i++) {
     const base::DictionaryValue* entry_value;
     if (!entries->GetDictionary(i, &entry_value)) {
       SignalError();
@@ skipping 109 matching lines @@
     base::File::Error result,
     const base::File::Info& info) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   content::BrowserThread::PostTask(content::BrowserThread::IO,
                                    FROM_HERE,
                                    base::Bind(callback_, result, info));
   container_->RemoveOperation(this);
 }
 
 }  // namespace local_discovery