Update existing uses of /wd4267 to use the GN config

third_party/libjingle/BUILD.gn

Index: third_party/libjingle/BUILD.gn
diff --git a/third_party/libjingle/BUILD.gn b/third_party/libjingle/BUILD.gn
index 6357b92b9694cfe40f4242cd1903047969ba2f6a..fc13ff1038eaceee09ff54cdf48854621f015711 100644
--- a/third_party/libjingle/BUILD.gn
+++ b/third_party/libjingle/BUILD.gn
@@ -256,6 +256,10 @@ static_library("libjingle") {
     "$p2p_dir/base/constants.cc",
     "$p2p_dir/base/constants.h",
   ]
+
+  # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+
   public_deps = [
     ":jingle_deps",
   ]
@@ -266,10 +270,7 @@ static_library("libjingle") {
 
   # From libjingle_common.gypi's conditions list.
   if (is_win) {
-    cflags = [
-      "/wd4005",
-      "/wd4267",
-    ]
+    cflags = [ "/wd4005" ]
   }
 
   configs += [ ":jingle_unexported_configs" ]