Delete all test isolate file.

sandbox/sbox_validation_tests.isolate

-# Copyright 2015 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.
-
-# Because of a limitation in isolate_driver.py, this file needs to be in
-# the same directory as the main .gyp file.
-
-{
-  'conditions': [
-    ['OS=="win"', {
-      'variables': {
-        'command': [
-          '<(PRODUCT_DIR)/sbox_validation_tests.exe',
-        ],
-      },
-    }],
-    ['OS=="win" and target_arch=="ia32"', {
-      'variables': {
-        'files': [
-          '<(PRODUCT_DIR)/wow_helper.exe',
-        ],
-      },
-    }],
-  ],
-  'includes': [
-    '../base/base.isolate',
-  ],
-}