Decoupling rtc_base from apple specific code [without cyclic deps]

webrtc/rtc_tools/network_tester/BUILD.gn

Index: webrtc/rtc_tools/network_tester/BUILD.gn
diff --git a/webrtc/rtc_tools/network_tester/BUILD.gn b/webrtc/rtc_tools/network_tester/BUILD.gn
index 4a262fc9be587741adb352c22b7944ef8ef17f0c..53da96722997e5c99649b4ce31b721f70053acc6 100644
--- a/webrtc/rtc_tools/network_tester/BUILD.gn
+++ b/webrtc/rtc_tools/network_tester/BUILD.gn
@@ -118,6 +118,10 @@ if (rtc_enable_protobuf) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
+
+    if (is_ios || is_mac) {
+      deps += [ "../../rtc_base:rtc_base_apple" ]
+    }
   }
 }