Fix ios_chrome_unittests to crash on DCHECK failure.

ios/chrome/test/BUILD.gn

 # 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.
 
 import("//ios/build/config.gni")
 import("//ios/public/provider/chrome/browser/build_config.gni")
 import("//testing/test.gni")
 
 # All tests needs to be listed in that target to be built as part of
 # "gn_all" target (i.e. by the bots).
@@ skipping 15 matching lines @@
     "ios_chrome_scoped_testing_local_state.cc",
     "ios_chrome_scoped_testing_local_state.h",
     "ios_chrome_unit_test_suite.h",
     "ios_chrome_unit_test_suite.mm",
     "testing_application_context.h",
     "testing_application_context.mm",
   ]
 
   deps = [
     "//base",
+    "//base/test:test_support",
     "//components/content_settings/core/common",
     "//components/network_time",
     "//components/prefs",
     "//components/prefs:test_support",
     "//ios/chrome/browser",
     "//ios/chrome/browser/browser_state:browser_state_impl",
     "//ios/chrome/browser/prefs:browser_prefs",
     "//ios/public/provider/chrome/browser",
     "//ios/public/provider/chrome/browser:test_support",
     "//ios/web",
@@ skipping 132 matching lines @@
     "//ios/chrome/browser/web:unit_tests",
     "//ios/chrome/browser/web:unit_tests_internal",
     "//ios/chrome/browser/web_resource:unit_tests",
     "//ios/chrome/common:unit_tests",
     "//ios/chrome/test/base:unit_tests",
     "//ios/web/public/image_fetcher:unit_tests",
   ]
 
   assert_no_deps = ios_assert_no_deps
 }