Fix errors found in Mac gn component builds

sync/BUILD.gn

 # Copyright 2014 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/features.gni")
 import("//testing/test.gni")
 
 component("sync") {
   public_deps = [
     ":sync_core",
@@ skipping 403 matching lines @@
     "//url",
     "//sync/internal_api/attachments/proto",
     "//sync/protocol",
   ]
 
   if (is_chromeos) {
     # Required by get_session_name.cc on Chrome OS.
     deps += [ "//chromeos" ]
   }
 
+  if (is_mac) {
+    libs = [
+      # Required by get_session_name_mac.mm on Mac.
+      "SystemConfiguration.framework",
+    ]
+  }
+
   defines = [ "SYNC_IMPLEMENTATION" ]
   configs += [ "//build/config/compiler:wexit_time_destructors" ]
 }
 
 # GYP version: sync/sync_tests.gypi:test_support_sync_core
 static_library("test_support_sync_core") {
   testonly = true
   sources = [
     "internal_api/public/base/model_type_test_util.cc",
     "internal_api/public/base/model_type_test_util.h",
@@ skipping 382 matching lines @@
       ":fake_server_jni",
       ":sync_core",
       ":test_support_sync_fake_server",
       "//base",
       "//sync/protocol:protocol",
       "//testing/gtest",
       "//url:url",
     ]
   }
 }