resources: Prevent including the same resource in multiple pack files.

components/components_unittests.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.
 {
   'conditions': [
     ['use_x11==0', {
       'variables': {
         'command': [
           '../testing/test_env.py',
           '<(PRODUCT_DIR)/components_unittests<(EXECUTABLE_SUFFIX)',
@@ skipping 29 matching lines @@
           'test/data/',
           '<(PRODUCT_DIR)/components_tests_resources.pak',
         ],
       },
     }],
     ['OS=="linux" or OS=="mac" or OS=="win"', {
       'variables': {
         'files': [
           '../testing/test_env.py',
           '<(PRODUCT_DIR)/components_unittests<(EXECUTABLE_SUFFIX)',
+          '<(PRODUCT_DIR)/ui_test.pak',
         ],
       },
     }],
     ['OS=="linux"', {
       'variables': {
         'files': [
           '<(PRODUCT_DIR)/libffmpegsumo.so',
           '<(PRODUCT_DIR)/libosmesa.so',
         ],
       },
@@ skipping 30 matching lines @@
           '<(PRODUCT_DIR)/osmesa.so.dSYM/',
         ],
       },
     }],
   ],
   'includes': [
     '../base/base.isolate',
     '../third_party/angle/angle.isolate',
   ],
 }