Fix asan tests failing on swarming. They need libc++.so.

content/content_unittests.isolate

 # Copyright (c) 2013 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" or OS=="mac" or OS=="win"', {
       'variables': {
         'isolate_dependency_untracked': [
           '../media/test/data/',
           'test/data/',
@@ skipping 75 matching lines @@
     }],
     ['OS=="win" and (fastbuild==0 or fastbuild==1)', {
       'variables': {
         'isolate_dependency_untracked': [
           '<(PRODUCT_DIR)/content_unittests.exe.pdb',
         ],
       },
     }],
   ],
   'includes': [
-    '../third_party/icu/icu.isolate',
+    '../base/base.isolate',
   ],
 }