Add three missing test files to gn builds

components/translate/core/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/ui.gni")
 
 source_set("browser") {
   sources = [
     "language_state.cc",
     "language_state.h",
@@ skipping 62 matching lines @@
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
     "language_state_unittest.cc",
     "mock_translate_driver.cc",
     "mock_translate_driver.h",
     "translate_browser_metrics_unittest.cc",
     "translate_language_list_unittest.cc",
+    "translate_manager_unittest.cc",
     "translate_prefs_unittest.cc",
     "translate_script_unittest.cc",
   ]
   deps = [
     ":browser",
     "//base",
     "//components/pref_registry:test_support",
     "//components/prefs",
     "//components/translate/core/common",
     "//net:test_support",
     "//testing/gtest",
   ]
   if (!use_aura) {
     sources += [ "translate_ui_delegate_unittest.cc" ]
     deps += [ "//components/infobars/core" ]
   }
 }