Ignores warning for SecRandomCopyBytes() using Xcode 8

webrtc/examples/BUILD.gn

 # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("../build/webrtc.gni")
 if (is_android) {
@@ skipping 306 matching lines @@
     # adds these flags so to cancel them out they need to come from a config and
     # cannot be on the target directly.
     cflags = [
       "-Wno-deprecated-declarations",
       "-Wno-nonnull",
       "-Wno-objc-missing-property-synthesis",
       "-Wno-semicolon-before-method-body",
       "-Wno-unused-variable",
     ]
 
-    # Enabled for cflags_objc in build/config/compiler/BUILD.gn.
-    cflags_objc = [ "-Wno-objc-missing-property-synthesis" ]
+    cflags_objc = [
+      # Enabled for cflags_objc in build/config/compiler/BUILD.gn.
+      "-Wno-objc-missing-property-synthesis",
+
+      # Hide the warning for SecRandomCopyBytes(), until we update to upstream.
+      # https://bugs.chromium.org/p/webrtc/issues/detail?id=6396
+      "-Wno-unused-result",
+    ]
 
     if (is_mac) {
       cflags += [ "-Wno-partial-availability" ]
     }
   }
 
   rtc_source_set("socketrocket") {
     sources = [
       "objc/AppRTCDemo/third_party/SocketRocket/SRWebSocket.h",
       "objc/AppRTCDemo/third_party/SocketRocket/SRWebSocket.m",
@@ skipping 167 matching lines @@
       "//webrtc/system_wrappers:field_trial_default",
       "//webrtc/system_wrappers:metrics_default",
     ]
     if (is_clang) {
       # Suppress warnings from the Chromium Clang plugin.
       # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
   }
 }