Split //ios/chrome/browser in multiple targets.

ios/chrome/browser/ui/voice/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.
 
 source_set("voice") {
   sources = [
     "text_to_speech_player.h",
     "text_to_speech_player.mm",
     "voice_search_notification_names.h",
     "voice_search_notification_names.mm",
   ]
 
   deps = [
     "//base",
   ]
 
   libs = [ "AVFoundation.framework" ]
 }
 
 source_set("unit_tests") {
   testonly = true
 
   sources = [
     "text_to_speech_player_unittest.mm",
   ]
 
   deps = [
+    ":voice_unit_tests_bundle_data",
     "//base",
     "//base/test:test_support",
     "//ios/web",
     "//ios/web:test_support",
     "//testing/gtest",
     "//url",
   ]
 
   public_deps = [
     ":voice",
   ]
 }
+
+bundle_data("voice_unit_tests_bundle_data") {
+  visibility = [ ":unit_tests" ]
+  testonly = true
+  sources = [
+    "//ios/chrome/test/data/voice/test_sound.m4a",
+  ]
+  outputs = [
+    "{{bundle_resources_dir}}/{{source_root_relative_dir}}/" +
+        "{{source_file_part}}",
+  ]
+}