Fix PPAPI TestCase so individual tests can be run more than once.

ppapi/tests/test_file_io.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 "ppapi/tests/test_file_io.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <string.h>
@@ skipping 1120 matching lines @@
 // This is a regression test for crbug.com/243241.
 std::string TestFileIO::TestRequestOSFileHandleWithOpenExclusive() {
   TestCompletionCallback callback(instance_->pp_instance(), callback_type());
 
   pp::FileSystem file_system(instance_, PP_FILESYSTEMTYPE_LOCALTEMPORARY);
   pp::FileRef file_ref(file_system, "/file_os_fd2");
 
   callback.WaitForResult(file_system.Open(1024, callback.GetCallback()));
   ASSERT_EQ(PP_OK, callback.result());
 
+  // Open with PP_FILEOPENFLAG_CREATE and PP_FILEOPENFLAG_EXCLUSIVE will fail
+  // if the file already exists. Delete it here to make sure it does not.
+  callback.WaitForResult(file_ref.Delete(callback.GetCallback()));
+
   pp::FileIO_Private file_io(instance_);
   callback.WaitForResult(file_io.Open(file_ref,
                                       PP_FILEOPENFLAG_CREATE |
                                       PP_FILEOPENFLAG_READ |
                                       PP_FILEOPENFLAG_WRITE |
                                       PP_FILEOPENFLAG_EXCLUSIVE,
                                       callback.GetCallback()));
   ASSERT_EQ(PP_OK, callback.result());
 
   TestCompletionCallbackWithOutput<pp::PassFileHandle> output_callback(
@@ skipping 254 matching lines @@
   if ((invalid_combination && callback.result() == PP_OK) ||
       (!invalid_combination &&
        ((callback.result() == PP_OK) != create_if_doesnt_exist))) {
     return ReportOpenError(open_flags);
   }
 
   return std::string();
 }
 
 // TODO(viettrungluu): Test Close(). crbug.com/69457