Suppress psabi warnings in GN build.

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 if (cpu_arch == "arm") {
   import("//build/config/arm.gni")
 }
 if (is_posix) {
   import("//build/config/gcc/gcc_version.gni")
@@ skipping 585 matching lines @@
         # Clang considers the `register` keyword as deprecated, but e.g.
         # code generated by flex (used in angle) contains that keyword.
         # http://crbug.com/255186
         "-Wno-deprecated-register",
 
         # Clang spots more unused functions.
         "-Wno-unused-function",
       ]
     }
 
+    # Suppress warnings about ABI changes on ARM (Clang doesn't support this).

[Nico, 2014/05/21 19:43:59]

"support" is a strange word for working around silly warnings it doesn't print
in the first place :-P

[brettw, 2014/05/21 20:07:32]

I clarified this.

+    if (cpu_arch == "arm" && !is_clang) {
+      cflags += [ "-Wno-psabi" ]
+    }
+
     if (is_android) {
       # Disable any additional warnings enabled by the Android build system but
       # which chromium does not build cleanly with (when treating warning as
       # errors).
       cflags += [
         "-Wno-extra",
         "-Wno-ignored-qualifiers",
         "-Wno-type-limits",
       ]
       cflags_cc = [
@@ skipping 161 matching lines @@
   } else {
     cflags = [ "-g1" ]
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }