Remove hotword installation code at compile time if hotwording disabled.

chrome/browser/BUILD.gn

 # Copyright 2014 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/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//chrome/common/features.gni")
 import("//media/media_options.gni")
 import("//third_party/protobuf/proto_library.gni")
 
 # //build/config/android/rules.gni imports //tools/grit/grit_rule.gni, which
 # produces a conflict for the "grit" template so we have to only include one.
 if (is_android) {
   import("//build/config/android/rules.gni")
 } else {
   import("//tools/grit/grit_rule.gni")
 }
 if (is_desktop_linux) {
   import("//build/config/linux/pkg_config.gni")
 }
 
-declare_args() {
-  # 'Ok Google' hotwording is disabled by default. Set to true to enable. (This
-  # will download a closed-source NaCl module at startup.) Chrome-branded
-  # ChromeOS builds have this enabled by default.
-  enable_hotwording = is_chrome_branded && is_chromeos
-}
-
 additional_modules_list_file =
     "$root_gen_dir/chrome/browser/internal/additional_modules_list.txt"
 
 gypi_values = exec_script("//build/gypi_to_gn.py",
                           [ rebase_path("../chrome_browser.gypi") ],
                           "scope",
                           [ "../chrome_browser.gypi" ])
 
 if (is_win) {
   # This is in a separate config so the flags can be applied to dependents.
@@ skipping 518 matching lines @@
         deps += [ "//chrome/browser/safe_browsing/incident_reporting:state_store_data_proto" ]
       }
     } else if (safe_browsing_mode == 2) {
       sources +=
           rebase_path(gypi_values.chrome_browser_safe_browsing_mobile_sources,
                       ".",
                       "//chrome")
     }
   }
 
-  if (enable_hotwording) {
-    defines += [ "ENABLE_HOTWORDING" ]
-  }
-
   if (is_linux) {
     deps += [ "//device/media_transfer_protocol" ]
   }
 
   if (use_udev) {
     deps += [ "//device/udev_linux" ]
   }
 
   if (is_linux && !is_chromeos) {
     deps += [ "//third_party/speech-dispatcher" ]
@@ skipping 748 matching lines @@
         rebase_path(gypi_values.chrome_browser_rlz_sources, ".", "//chrome")
     deps = [
       "//components/google/core/browser",
       "//components/omnibox/browser",
       "//components/rlz",
       "//components/search_engines",
       "//rlz:rlz_lib",
     ]
   }
 }