Update existing uses of /wd4267 to use the GN config

chrome/common/net/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/crypto.gni")
 
 # GYP version: chrome/chrome_common.gypi:common_net
 static_library("net") {
   sources = [
     "net_resource_provider.cc",
@@ skipping 39 matching lines @@
   }
 
   if (is_android) {
     sources -= [
       "x509_certificate_model.cc",
       "x509_certificate_model_openssl.cc",
     ]
     deps += [ "//third_party/boringssl" ]
   }
 
-  if (is_win) {
-    cflags = [ "/wd4267" ]
-  }
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 }