Make GN Android build link executables

third_party/libevent/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.
 
 static_library("libevent") {
   sources = [
     "buffer.c",
-    "epoll.c",
-    "epoll_sub.c",
     "evbuffer.c",
     "evdns.c",
     "event.c",
     "event_tagging.c",
     "evrpc.c",
     "evutil.c",
     "http.c",
-    "kqueue.c",
     "log.c",
     "poll.c",
     "select.c",
     "signal.c",
     "strlcpy.c",
   ]
 
   defines = [ "HAVE_CONFIG_H" ]
 
-  if (is_linux) {
-    libs = [ "rt" ]
-  } else {
-    sources -= [ "epoll.c", "epoll_sub.c" ]
-  }
-
-  if (is_mac) {
+  if (is_mac || is_ios) {
+    sources += [ "kqueue.c" ]
     include_dirs = [ "mac" ]
   } else if (is_linux) {
+    sources += [ "epoll.c" ]
     include_dirs = [ "linux" ]
-    sources -= [ "kqueue.c" ]
+    libs = [ "rt" ]
   } else if (is_android) {
+    sources += [ "epoll.c" ]
     include_dirs = [ "android" ]
-    sources -= [ "kqueue.c" ]
   }
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
 }