Turn on warnings as errors for (most) third_party code on Windows

skia/skia.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.
 
 {
   'targets': [
     {
       'target_name': 'skia',
       'type': '<(component)',
       'variables': {
@@ skipping 414 matching lines @@
         '../third_party/skia/include/images',
         '../third_party/skia/include/pdf',
         '../third_party/skia/include/pipe',
         '../third_party/skia/include/ports',
         '../third_party/skia/include/utils',
         '../third_party/skia/src/core',
         '../third_party/skia/src/gpu',
         '../third_party/skia/src/sfnt',
         '../third_party/skia/src/utils',
       ],
-      'msvs_disabled_warnings': [4244, 4267, 4341, 4345, 4390, 4554, 4800],
+      'msvs_disabled_warnings': [4244, 4267, 4341, 4345, 4390, 4554, 4748, 4800],
       'defines': [
         'SK_GAMMA_SRGB',
         #'SK_GAMMA_APPLY_TO_A8',
         'SK_BUILD_NO_IMAGE_ENCODE',
         'GR_GL_CUSTOM_SETUP_HEADER="GrGLConfig_chrome.h"',
         'GR_STATIC_RECT_VB=1',
         'GR_AGGRESSIVE_SHADER_OPTS=1',
         'SK_DISABLE_FAST_AA_STROKE_RECT',
         'SK_DEFERRED_CANVAS_USES_GPIPE=1',
         
@@ skipping 507 matching lines @@
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
         'ext/image_operations_bench.cc',
       ],
     },
   ],
 }