Update existing uses of /wd4267 to use the GN config

crypto/BUILD.gn

Index: crypto/BUILD.gn
diff --git a/crypto/BUILD.gn b/crypto/BUILD.gn
index f6c45aad72d3b55c99334d9c91bdca793a4699b1..d71719702139107d369e950dfbce78823a242882 100644
--- a/crypto/BUILD.gn
+++ b/crypto/BUILD.gn
@@ -93,6 +93,9 @@ component("crypto") {
     "third_party/nss/sha512.cc",
   ]
 
+  # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+
   deps = [
     ":platform",
     "//base",
@@ -126,11 +129,6 @@ component("crypto") {
     deps += [ "//third_party/android_tools:cpu_features" ]
   }
 
-  if (is_win) {
-    # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
-    cflags = [ "/wd4267" ]
-  }
-
   if (use_openssl) {
     # Remove NSS files when using OpenSSL
     sources -= [