gn win: disable 4267 (need for win x64)

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index 84beb15e2c6368595fc0245dfd4b88cd20767cf3..a0cdf66228578a5818b925c1967e118895b94dda 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -858,7 +858,7 @@ component("base") {
     ]
 
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
-    #cflags = [ "/wd4267" ]
+    cflags = [ "/wd4267" ]
 
     libs = [
       "cfgmgr32.lib",
@@ -1016,6 +1016,11 @@ component("i18n") {
     configs -= [ "//build/config/compiler:optimize" ]
     configs += [ "//build/config/compiler:optimize_max" ]
   }
+
+  if (is_win) {
+    # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+    cflags = [ "/wd4267" ]
+  }
 }
 
 source_set("prefs") {