PNaCl cleanup: Simplify error checking when opening temp files

components/nacl/renderer/plugin/temporary_file.cc

 // Copyright (c) 2012 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 "components/nacl/renderer/plugin/temporary_file.h"
 
 #include "base/logging.h"
 #include "build/build_config.h"
 #include "components/nacl/renderer/plugin/plugin.h"
 #include "components/nacl/renderer/plugin/utility.h"
 #include "ppapi/c/private/pp_file_handle.h"
 #include "ppapi/cpp/core.h"
 #include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/module.h"
 
 namespace plugin {
 
 TempFile::TempFile(Plugin* plugin, PP_FileHandle handle)
     : plugin_(plugin),
       file_handle_(handle) { }
 
 TempFile::~TempFile() { }
 
-int32_t TempFile::CheckValidity() {
-  if (!file_handle_.IsValid())
-    return PP_ERROR_FAILED;
-  return PP_OK;
-}
-
 bool TempFile::Reset() {
   // file_handle_, read_wrapper_ and write_wrapper_ are all backed by the
   // same file handle/descriptor, so resetting the seek position of one
   // will reset them all.
   int64_t newpos = file_handle_.Seek(base::File::FROM_BEGIN, 0);
   return newpos == 0;
 }
 
 int64_t TempFile::GetLength() {
   return file_handle_.GetLength();
 }
 
 PP_FileHandle TempFile::TakeFileHandle() {
   DCHECK(file_handle_.IsValid());
   return file_handle_.TakePlatformFile();
 }
 
 PP_FileHandle TempFile::GetFileHandle() {
   DCHECK(file_handle_.IsValid());
   return file_handle_.GetPlatformFile();
 }
 
 }  // namespace plugin