Update existing uses of /wd4267 to use the GN config

components/url_fixer/BUILD.gn

Index: components/url_fixer/BUILD.gn
diff --git a/components/url_fixer/BUILD.gn b/components/url_fixer/BUILD.gn
index bf29f3523db140fc16138ccf95cf596d7fcbdd4e..93eac1f3d2828847c2f8bdec63cf27be478a87a6 100644
--- a/components/url_fixer/BUILD.gn
+++ b/components/url_fixer/BUILD.gn
@@ -8,13 +8,11 @@ static_library("url_fixer") {
     "url_fixer.h",
   ]
 
+  # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+
   deps = [
     "//base",
     "//net",
   ]
-
-  if (is_win) {
-    # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
-    cflags = [ "/wd4267" ]
-  }
 }