Include icu.isolate instead of listing icudt.dll

chrome/unit_tests.isolate

 # 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.
 {
   'conditions': [
     ['OS=="android" or OS=="linux"', {
       'variables': {
         'isolate_dependency_untracked': [
           '<(PRODUCT_DIR)/test_data/',
         ],
@@ skipping 85 matching lines @@
           '<(PRODUCT_DIR)/test_data/chrome/browser/resources/print_preview/',
           '<(PRODUCT_DIR)/test_data/chrome/test/data/unit/',
           '<(PRODUCT_DIR)/test_data/ui/',
         ],
       },
     }],
     ['OS=="win"', {
       'variables': {
         'isolate_dependency_tracked': [
           '<(PRODUCT_DIR)/ffmpegsumo.dll',
-          '<(PRODUCT_DIR)/icudt.dll',
         ],
         'isolate_dependency_untracked': [
           '../ppapi/lib/gl/include/KHR/',
           '../skia/ext/data/',
           '../ui/base/glib/',
         ],
       },
     }],
   ],
+  'includes': [
+    '../third_party/icu/icu.isolate',
+  ],
 }