Update existing uses of /wd4267 to use the GN config

components/signin/core/browser/BUILD.gn

Index: components/signin/core/browser/BUILD.gn
diff --git a/components/signin/core/browser/BUILD.gn b/components/signin/core/browser/BUILD.gn
index 4f4f77677e27287036a04e52e95a4b2e222bb9b0..819b4181eae2815f5bdd62cf22cb6c416b87cad0 100644
--- a/components/signin/core/browser/BUILD.gn
+++ b/components/signin/core/browser/BUILD.gn
@@ -43,6 +43,8 @@ static_library("browser") {
     "webdata/token_web_data.h",
   ]
 
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+
   deps = [
     "//base",
     "//crypto",
@@ -67,11 +69,6 @@ static_library("browser") {
   if (is_chromeos) {
     sources -= [ "signin_manager.cc" ]
   }
-
-  if (is_win) {
-    # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
-    cflags = [ "/wd4267" ]
-  }
 }
 
 static_library("test_support") {