[ios] Adds a VoiceSearchController interface to the provider layer.

ios/chrome/browser/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("//build/config/features.gni")
 import("//ios/web/js_compile.gni")
 import("//third_party/protobuf/proto_library.gni")
 
 declare_args() {
   google_test_gaia_client_id = ""
@@ skipping 660 matching lines @@
     "//components/user_prefs",
     "//components/variations",
     "//components/variations/service",
     "//components/version_info",
     "//components/version_ui",
     "//components/web_resource",
     "//components/webdata_services",
     "//google_apis",
     "//ios/chrome/browser/signin",
     "//ios/chrome/browser/variations:ios_chrome_ui_string_overrider_factory",
+    "//ios/chrome/browser/voice:prefs",
     "//ios/chrome/common",
     "//ios/chrome/common/app_group",
     "//ios/chrome/common/physical_web",
     "//ios/net",
     "//ios/public/provider/chrome/browser",
     "//ios/public/provider/web",
     "//ios/web",
     "//ios/web:user_agent",
     "//ios/web/public/app",
     "//net",
@@ skipping 142 matching lines @@
     "//ios/public/provider/chrome/browser",
     "//ios/public/provider/chrome/browser:test_support",
     "//ios/web",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
     "//ui/base",
     "//url",
   ]
 }