Fix PP_FileOpenFlags_Dev handling:

webkit/fileapi/file_system_operation.cc

 // Copyright (c) 2011 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 "webkit/fileapi/file_system_operation.h"
 
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "net/base/escape.h"
 #include "net/url_request/url_request_context.h"
@@ skipping 528 matching lines @@
   FileSystemType type;
   FileSystemFileUtil* file_system_file_util;
   if (file_flags & (
       (base::PLATFORM_FILE_ENUMERATE | base::PLATFORM_FILE_TEMPORARY |
        base::PLATFORM_FILE_HIDDEN))) {
     delete this;
     return;
   }
   if (file_flags &
       (base::PLATFORM_FILE_CREATE | base::PLATFORM_FILE_OPEN_ALWAYS |
-       base::PLATFORM_FILE_CREATE_ALWAYS |
+       base::PLATFORM_FILE_CREATE_ALWAYS | base::PLATFORM_FILE_OPEN_TRUNCATED |
        base::PLATFORM_FILE_WRITE | base::PLATFORM_FILE_EXCLUSIVE_WRITE |
-       base::PLATFORM_FILE_DELETE_ON_CLOSE | base::PLATFORM_FILE_TRUNCATE |
+       base::PLATFORM_FILE_DELETE_ON_CLOSE |
        base::PLATFORM_FILE_WRITE_ATTRIBUTES)) {
     if (!VerifyFileSystemPathForWrite(path, true /* create */, &origin_url,
         &type, &virtual_path, &file_system_file_util)) {
       delete this;
       return;
     }
   } else {
     if (!VerifyFileSystemPathForRead(path, &origin_url, &type, &virtual_path,
         &file_system_file_util)) {
       delete this;
@@ skipping 306 matching lines @@
   }
   DCHECK(file_system_file_util);
   *file_system_file_util =
       file_system_context()->path_manager()->GetFileSystemFileUtil(*type);
   DCHECK(*file_system_file_util);
 
   return true;
 }
 
 }  // namespace fileapi