Decoupling rtc_base from apple specific code [without cyclic deps]

webrtc/sdk/BUILD.gn

 # Copyright 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")
 if (is_ios) {
@@ skipping 46 matching lines @@
       "objc/Framework/Classes/Common/helpers.h",
       "objc/Framework/Classes/Common/helpers.mm",
       "objc/Framework/Headers/WebRTC/RTCDispatcher.h",
       "objc/Framework/Headers/WebRTC/RTCFieldTrials.h",
       "objc/Framework/Headers/WebRTC/RTCLogging.h",
       "objc/Framework/Headers/WebRTC/RTCMacros.h",
     ]
 
     deps = [
       "../base:rtc_base",
+      "../rtc_base:rtc_base_apple",
     ]
     configs += [ "..:common_objc" ]
 
     public_configs = [ ":objc_common_config" ]
 
     if (is_ios) {
       sources += [
         "objc/Framework/Classes/Common/UIDevice+RTCDevice.mm",
         "objc/Framework/Headers/WebRTC/UIDevice+RTCDevice.h",
       ]
@@ skipping 536 matching lines @@
           "-all_load",
           "-install_name",
           "@rpath/$output_name.framework/$output_name",
         ]
 
         deps = [
           ":objc_audio",
           ":objc_peerconnection",
           ":objc_ui",
           "../base:rtc_base_approved",
+          "../rtc_base:rtc_base_apple",
           "../system_wrappers:field_trial_default",
           "../system_wrappers:metrics_default",
         ]
 
         libs = [
           "AVFoundation.framework",
           "CoreGraphics.framework",
           "CoreMedia.framework",
           "GLKit.framework",
         ]
@@ skipping 87 matching lines @@
         public_deps = [
           "$rtc_libyuv_dir",
         ]
       } else {
         # Need to add a directory normally exported by libyuv.
         include_dirs = [ "$rtc_libyuv_dir/include" ]
       }
     }
   }
 }