Use bundle_data and create_bundle to add support for iOS app bundle.

base/BUILD.gn

 # 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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 1588 matching lines @@
       sources = [
         "profiler/test_support_library.cc",
       ]
       deps = [
         "//build/config/sanitizers:deps",
       ]
     }
   }
 }
 
+if (is_ios) {
+  bundle_data("base_unittests_bundle_data") {
+    sources = [
+      "test/data",
+    ]
+    outputs = [
+      "{{bundle_resources_dir}}/{{source_root_relative_dir}}/{{source_file_part}}",
+    ]
+  }
+}
+
 test("base_unittests") {
   sources = [
     "allocator/tcmalloc_unittest.cc",
     "android/application_status_listener_unittest.cc",
     "android/content_uri_utils_unittest.cc",
     "android/jni_android_unittest.cc",
     "android/jni_array_unittest.cc",
     "android/jni_string_unittest.cc",
     "android/library_loader/library_prefetcher_unittest.cc",
     "android/path_utils_unittest.cc",
@@ skipping 240 matching lines @@
     ":i18n",
     ":message_loop_tests",
     "//base/test:run_all_unittests",
     "//base/test:test_support",
     "//base/third_party/dynamic_annotations",
     "//testing/gmock",
     "//testing/gtest",
     "//third_party/icu",
   ]
 
+  if (is_ios) {
+    deps += [ ":base_unittests_bundle_data" ]
+  }
+
   # Some unittests depend on the ALLOCATOR_SHIM macro.
   configs += [ "//base/allocator:allocator_shim_define" ]
 
   data = [
     "test/data/",
   ]
 
   # Allow more direct string conversions on platforms with native utf8
   # strings
   if (is_mac || is_ios || is_chromeos) {
@@ skipping 289 matching lines @@
 
   # GYP: //base.gyp:base_java_unittest_support
   android_library("base_java_unittest_support") {
     deps = [
       ":base_java",
     ]
     java_files =
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }