Decoupling rtc_base from apple specific code [without cyclic deps]

webrtc/BUILD.gn

Index: webrtc/BUILD.gn
diff --git a/webrtc/BUILD.gn b/webrtc/BUILD.gn
index a4cc0eed0d6bb015e9fe365e11744157946953db..b42a9b418a15c6e81e919147e3c25d2901fa45d9 100644
--- a/webrtc/BUILD.gn
+++ b/webrtc/BUILD.gn
@@ -275,6 +275,10 @@ if (!build_with_chromium) {
       defines += [ "ENABLE_RTC_EVENT_LOG" ]
       deps += [ "logging:rtc_event_log_proto" ]
     }
+
+    if (is_ios) {
+      deps += [ "rtc_base:rtc_base_apple" ]
+    }
   }
 
   if (rtc_include_tests) {
@@ -333,6 +337,9 @@ if (!build_with_chromium) {
           "logging:rtc_event_log2rtp_dump",
         ]
       }
+      if (is_ios || is_mac) {
+        deps += [ "rtc_base:rtc_base_apple" ]
+      }
     }
   }
 }
@@ -416,7 +423,10 @@ if (rtc_include_tests) {
     }
 
     if (is_ios || is_mac) {
-      deps += [ "sdk:objc_sdk_unittests" ]
+      deps += [
+        "rtc_base:rtc_base_apple",
+        "sdk:objc_sdk_unittests",
+      ]
     }
   }
 
@@ -463,6 +473,9 @@ if (rtc_include_tests) {
     if (is_ios) {
       deps += [ ":video_engine_tests_bundle_data" ]
     }
+    if (is_ios || is_mac) {
+      deps += [ "rtc_base:rtc_base_apple" ]
+    }
   }
 
   webrtc_perf_tests_resources = [
@@ -513,6 +526,9 @@ if (rtc_include_tests) {
     if (is_ios) {
       deps += [ ":webrtc_perf_tests_bundle_data" ]
     }
+    if (is_ios || is_mac) {
+      deps += [ "rtc_base:rtc_base_apple" ]
+    }
   }
 
   rtc_test("webrtc_nonparallel_tests") {
@@ -524,6 +540,9 @@ if (rtc_include_tests) {
       deps += [ "//testing/android/native_test:native_test_support" ]
       shard_timeout = 900
     }
+    if (is_ios || is_mac) {
+      deps += [ "rtc_base:rtc_base_apple" ]
+    }
   }
 
   if (is_android) {