Translate: do not show the context menu entry when the feature is disabled

components/translate/core/common/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.
 
 static_library("common") {
   sources = [
     "language_detection_details.cc",
     "language_detection_details.h",
     "translate_constants.cc",
     "translate_constants.h",
     "translate_errors.h",
     "translate_metrics.cc",
     "translate_metrics.h",
-    "translate_pref_names.cc",
-    "translate_pref_names.h",
     "translate_switches.cc",
     "translate_switches.h",
     "translate_util.cc",
     "translate_util.h",
   ]
 
   deps = [
     "//base",
     "//url",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
     "translate_metrics_unittest.cc",
     "translate_util_unittest.cc",
   ]
   deps = [
     ":common",
     "//base",
     "//testing/gtest",
     "//url",
   ]
 }