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

gpu/gles2_conform_support/gles2_conform_test.gyp

 # Copyright (c) 2013 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': [
     'gles2_conform.gypi',
   ],
   'target_defaults': {
-    'msvs_disabled_warnings': [4005, 4013, 4018, 4101, 4716],
+    'msvs_disabled_warnings': [4005, 4013, 4101, 4716],
      'include_dirs': [
        '<(SHARED_INTERMEDIATE_DIR)/gles2_conform_test_embedded_data',
        '../../third_party/gles2_conform/GTF_ES/glsl/GTF/Source',
      ],
   },
   'targets': [
     {
       'target_name': 'gles2_conform_test',
       'type': 'executable',
       'dependencies': [
@@ skipping 105 matching lines @@
             ['OS=="win"', {
               'dependencies': [
                 '<(angle_path)/src/angle.gyp:libGLESv2',
                 '<(angle_path)/src/angle.gyp:libEGL',
               ],
               'defines': [
                 'EGLAPI=',
                 'EGLAPIENTRY=',
               ],
               'msvs_disabled_warnings': [
-                4018,  # signed/unsigned mismatch
                 4101,  # unreferenced local variable
                 4715,  # not all control paths return a value
                 4267,  # size_t/unsigned int conversion
               ],
               'defines!': [ 'NOMINMAX' ],
             }],
             ['OS=="mac"', {
               'defines': [
                 '_STDINT',
                 '_STDINT_H',
@@ skipping 103 matching lines @@
     }],
   ],
 }
 
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: