Remove ENABLE_LANGUAGE_DETECTION

chrome/chrome_tests_unit.gypi

 # Copyright 2012 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.
 {
   'targets': [
     {
       # This target contains mocks and test utilities that don't belong in
       # production libraries but are used by more than one test executable.
       'target_name': 'test_support_common',
       'type': 'static_library',
@@ skipping 2470 matching lines @@
           ],
         }],  # OS == android
         ['enable_themes==0', {
           'sources!': [
             'browser/ui/webui/theme_source_unittest.cc',
           ],
           'sources/': [
             ['exclude', '^browser/themes/'],
           ],
         }],
-        ['enable_language_detection==0', {
-          'sources!': [
-            'browser/language_usage_metrics_unittest.cc',
-          ],
-        }],
         ['toolkit_views==1', {
           'dependencies': [
             '../ui/views/views.gyp:views',
           ],
           'sources!': [
             'browser/ui/gtk/tabs/tab_renderer_gtk_unittest.cc',
           ],
         }, { # else: toolkit_views == 0
           'sources/': [
             ['exclude', '^browser/ui/views/'],
@@ skipping 141 matching lines @@
               # more details.
               'DebugInformationFormat': '3',
               'ProgramDataBaseFileName': '<(PRODUCT_DIR)/unit_tests.exe.pdb',
             },
           },
         },
       ],
     }],
   ],  # 'conditions'
 }