GN: Simplify config by unconditionalising a flag that nacl-clang recognises

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 05c7d13f0edc35b1c03ed952c94fd498fbfa4dec..7cc2c39da9422ac403c70b1ae5fa0ffb5aabef6e 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -1023,6 +1023,9 @@ if (is_clang) {
     # which we no longer use. Check if it makes sense to remove
     # this as well. http://crbug.com/316352
     "-Wno-unneeded-internal-declaration",
+
+    # TODO(hans): Get this cleaned up, http://crbug.com/428099
+    "-Wno-inconsistent-missing-override",
   ]
 
   if (is_posix && !is_mac && !is_ios) {
@@ -1038,9 +1041,6 @@ if (is_clang) {
   if (!is_nacl) {
     # Flags NaCl does not recognize.
     default_warning_flags += [
-      # TODO(hans): Get this cleaned up, http://crbug.com/428099
-      "-Wno-inconsistent-missing-override",
-
       # TODO(thakis): Enable this, crbug.com/507717
       "-Wno-shift-negative-value",
     ]