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

ios/public/provider/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/buildflag_header.gni")
 import("//ios/public/provider/chrome/browser/build_config.gni")
 
 source_set("browser") {
   sources = [
     "chrome_browser_provider.h",
@@ skipping 14 matching lines @@
     "ui/app_rating_prompt.h",
     "ui/default_ios_web_view_factory.h",
     "ui/default_ios_web_view_factory.mm",
     "ui/infobar_view_delegate.h",
     "ui/infobar_view_protocol.h",
     "ui/text_field_styling.h",
     "updatable_resource_provider.h",
     "updatable_resource_provider.mm",
     "voice/audio_session_controller.h",
     "voice/logo_animation_controller.h",
+    "voice/voice_search_controller.h",
+    "voice/voice_search_controller.mm",
+    "voice/voice_search_controller_delegate.h",
     "voice/voice_search_language.h",
     "voice/voice_search_language.mm",
+    "voice/voice_search_prefs.cc",
+    "voice/voice_search_prefs.h",
     "voice/voice_search_provider.h",
     "voice/voice_search_provider.mm",
   ]
 
   public_deps = [
     ":provider_flags",
   ]
 
   deps = [
     "//base",
@@ skipping 37 matching lines @@
   ]
 
   deps = [
     ":browser",
     "//base",
     "//components/signin/ios/browser:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }