Split //ios/public/provider/chrome/browser/* 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") {
   configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
+    "text_to_speech_player+subclassing.h",
     "text_to_speech_player.h",
     "text_to_speech_player.mm",
     "voice_search_notification_names.h",
     "voice_search_notification_names.mm",
   ]
 
   deps = [
     "//base",
   ]
 
@@ skipping 26 matching lines @@
   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}}",
   ]
 }