Decoupling rtc_base from Obj-C code

webrtc/rtc_base/BUILD.gn

Index: webrtc/rtc_base/BUILD.gn
diff --git a/webrtc/rtc_base/BUILD.gn b/webrtc/rtc_base/BUILD.gn
index 925f915aca4efd600f1d7adca70b55e8ca99a08c..2e56ba24793384398378b48c5a5e63458484d2f2 100644
--- a/webrtc/rtc_base/BUILD.gn
+++ b/webrtc/rtc_base/BUILD.gn
@@ -399,6 +399,35 @@ rtc_source_set("rtc_json") {
 }
 
 rtc_static_library("rtc_base") {
+  if (is_ios || is_mac) {
+    sources = [
+      "noop.mm",
+    ]
+    public_deps = [
+      ":objc_rtc_base",
+    ]
+  } else {
+    sources = [
+      "noop.cc",
+    ]
+    public_deps = [
+      ":rtc_base_generic",
+    ]
+  }
+}
+
+rtc_static_library("objc_rtc_base") {

[kjellander_webrtc, 2017/08/14 14:00:36]

How about rtc_base_objc?

[mbonadei, 2017/08/14 15:07:34]

Seems good to me. I also prefer the _objc suffix (I will update all the other
CLs in the next days).

+  sources = [
+    "applefilesystem.mm",
+    "thread_darwin.mm",
+  ]
+  public_deps = [
+    ":rtc_base_generic",
+  ]
+  visibility = [ ":rtc_base" ]
+}
+
+rtc_static_library("rtc_base_generic") {
   cflags = []
   cflags_cc = []
   libs = []
@@ -414,7 +443,6 @@ rtc_static_library("rtc_base") {
   all_dependent_configs = [ ":rtc_base_all_dependent_config" ]
 
   sources = [
-    "applefilesystem.mm",
     "asyncinvoker-inl.h",
     "asyncinvoker.cc",
     "asyncinvoker.h",
@@ -508,6 +536,11 @@ rtc_static_library("rtc_base") {
     "thread.h",
   ]
 
+  visibility = [

[kjellander_webrtc, 2017/08/14 14:00:36]

How about 
visibility = [ ":*" ]
to make maintenance a little easier.
Then move it up a few steps to make it consistent with most other targets.

[mbonadei, 2017/08/14 15:07:34]

I would like to keep it as private as possible because this is the real rtc_base
and I would like to avoid that a target depends on this one skipping the
proxy.

[kjellander_webrtc, 2017/08/15 08:40:58]

Fair enough.

+    ":rtc_base",
+    ":objc_rtc_base",
+  ]
+
   # TODO(henrike): issue 3307, make rtc_base build with the Chromium default
   # compiler settings.
   suppressed_configs += [ "//build/config/compiler:chromium_code" ]
@@ -567,10 +600,7 @@ rtc_static_library("rtc_base") {
   }
 
   if (is_ios || is_mac) {
-    sources += [
-      "macifaddrs_converter.cc",
-      "thread_darwin.mm",
-    ]
+    sources += [ "macifaddrs_converter.cc" ]
   }
 
   if (use_x11) {