win: /utf-8 for all code

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index fae310aa80ebb725d6f525985094fd9028bf6788..f3a69627b3b04726b55af755978481a6a7cd2ff7 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -840,6 +840,11 @@ config("default_warnings") {
     }
 
     cflags += [
+      # Assume UTF-8 by default to avoid code page dependencies.
+      "/utf-8",
+    ]
+
+    cflags += [
       # Warnings permanently disabled:
 
       # C4091: 'typedef ': ignored on left of 'X' when no variable is
@@ -1070,9 +1075,6 @@ config("default_warnings") {
 config("chromium_code") {
   if (is_win) {
     cflags = [ "/W4" ]  # Warning level 4.
-
-    # Assume UTF-8 by default to avoid code page dependencies.
-    cflags += [ "/utf-8" ]
   } else {
     cflags = [ "-Wall" ]
     if (treat_warnings_as_errors) {