Fix PP_FileOpenFlags_Dev handling:

webkit/fileapi/file_system_operation.cc

Index: webkit/fileapi/file_system_operation.cc
diff --git a/webkit/fileapi/file_system_operation.cc b/webkit/fileapi/file_system_operation.cc
index d3f1f379858a27d8f713e60b1d80cac6d89ba1c8..9692cb3bd471c9aec4360b4387b4eb18af7c24d6 100644
--- a/webkit/fileapi/file_system_operation.cc
+++ b/webkit/fileapi/file_system_operation.cc
@@ -546,9 +546,9 @@ void FileSystemOperation::OpenFile(const GURL& path,
   }
   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)) {