Include stlport through -isystem instead of -I.

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 382 matching lines @@
         "-I" + rebase_path("$android_src/external/stlport/stlport",
                            root_build_dir),
       ]
       libs += [
         "stlport",
       ]
     } else {
       android_stlport_root = "$android_ndk_root/sources/cxx-stl/stlport"
 
       cflags += [
-        "-I" + rebase_path("$android_stlport_root/stlport", root_build_dir)
+        "-isystem" + rebase_path("$android_stlport_root/stlport",
+                                 root_build_dir)
       ]
       lib_dirs += [ "$android_stlport_root/libs/$android_app_abi" ]
 
       if (component_mode == "shared_library") {
         libs += [ "stlport_shared" ]
       } else {
         libs += [ "stlport_static" ]
       }
     }
 
@@ skipping 416 matching lines @@
   } else {
     cflags = [ "-g1" ]
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }