GN: Add system_wrappers_unittests, tools and tools_unittests

webrtc/base/BUILD.gn

 # Copyright (c) 2014 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/config/crypto.gni")
 import("//build/config/ui.gni")
@@ skipping 157 matching lines @@
   } else {
     sources += [
       "logging.cc",
       "logging.h",
       "logging_mac.mm",
     ]
   }
 }
 
 static_library("rtc_task_queue") {
-  public_deps = [ ":rtc_base_approved" ]
+  public_deps = [
+    ":rtc_base_approved",
+  ]
   configs += [ "..:common_config" ]
 
   sources = [
     "task_queue.h",
     "task_queue_posix.h",
   ]
 
   if (rtc_build_libevent) {
-    deps = [ "//base/third_party/libevent" ]
+    deps = [
+      "//base/third_party/libevent",
+    ]
   }
 
   if (rtc_enable_libevent) {
     sources += [
       "task_queue_libevent.cc",
       "task_queue_posix.cc",
     ]
   } else {
     if (is_mac || is_ios) {
       sources += [
@@ skipping 349 matching lines @@
       "dl",
       "rt",
     ]
   }
 
   if (is_mac) {
     sources += [
       "macutils.cc",
       "macutils.h",
     ]
+    libs += [ "CoreServices.framework" ]  # For GetGestalt in macutils.cc.
   }
 
   if (is_win) {
     sources += [
       "win32.cc",
       "win32.h",
       "win32filesystem.cc",
       "win32filesystem.h",
       "win32securityerrors.cc",
       "win32window.cc",
@@ skipping 52 matching lines @@
     defines += [ "timezone=_timezone" ]
     sources -= [ "ifaddrs_converter.cc" ]
   }
 }
 
 source_set("gtest_prod") {
   sources = [
     "gtest_prod_util.h",
   ]
 }