Enable MSVC warning C4018 for various directories that seem to pass as-is.

third_party/cld/cld.gyp

 # Copyright (c) 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.
 
 {
   'includes': [
     '../../build/win_precompile.gypi',
   ],
   'targets': [
     {
@@ skipping 92 matching lines @@
         ],
       },
       'conditions': [
         ['OS=="win"', {
           'direct_dependent_settings': {
             'defines': [
               'COMPILER_MSVC',
             ],
           },
           # TODO(jschuh): C4267: http://crbug.com/167187 size_t -> int
-          'msvs_disabled_warnings': [4005, 4006, 4018, 4244, 4309, 4800, 4267],
+          'msvs_disabled_warnings': [4005, 4006, 4244, 4309, 4800, 4267],
         }, {
           'direct_dependent_settings': {
             'defines': [
               'COMPILER_GCC',
             ],
           },
         }],
       ],
     },
   ],
 }