Decoupling rtc_base from apple specific code [without cyclic deps]

webrtc/modules/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("../webrtc.gni")
 import("audio_coding/audio_coding.gni")
@@ skipping 66 matching lines @@
 
     if (is_android) {
       deps += [ "//testing/android/native_test:native_test_native_code" ]
       shard_timeout = 900
     }
 
     if (is_ios) {
       deps += [ ":modules_tests_bundle_data" ]
     }
 
+    if (is_ios || is_mac) {
+      deps += [ "../rtc_base:rtc_base_apple" ]
+    }
+
     if (!build_with_chromium && is_clang) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
     if (is_win) {
       cflags = [
         # TODO(phoglund): get rid of 4373 supression when
         # http://code.google.com/p/webrtc/issues/detail?id=261 is solved.
         # legacy warning for ignoring const / volatile in signatures.
         "/wd4373",
@@ skipping 152 matching lines @@
         "//testing/android/native_test:native_test_support",
       ]
       shard_timeout = 900
     }
     if (is_ios) {
       info_plist = "../test/ios/Info.plist"
       deps += [ ":modules_unittests_bundle_data" ]
       configs += [ "..:common_objc" ]
       ldflags = [ "-ObjC" ]
     }
+    if (is_ios || is_mac) {
+      deps += [ "../rtc_base:rtc_base_apple" ]
+    }
   }
 }