Allow building mojo_shell and non-graphical apps/services on a Mac

mojo/dart/embedder/BUILD.gn

Index: mojo/dart/embedder/BUILD.gn
diff --git a/mojo/dart/embedder/BUILD.gn b/mojo/dart/embedder/BUILD.gn
index c49a14052770477179e3bafe6c22c454379edcb0..21df1f0fcf0e575d415fe76c4e56e2504d0d6ffd 100644
--- a/mojo/dart/embedder/BUILD.gn
+++ b/mojo/dart/embedder/BUILD.gn
@@ -17,6 +17,7 @@ source_set("dart_controller_no_snapshot") {
     "dart_controller.cc",
     "dart_controller.h",
     "io/internet_address.h",
+    "io/internet_address_posix.cc",
     "mojo_dart_state.h",
     "mojo_io_natives.cc",
     "mojo_io_natives.h",
@@ -26,14 +27,6 @@ source_set("dart_controller_no_snapshot") {
     "vmservice.h",
   ]
 
-  if (is_linux) {
-    sources += [ "io/internet_address_linux.cc" ]
-  }
-
-  if (is_android) {
-    sources += [ "io/internet_address_android.cc" ]
-  }
-
   deps = [
     ":dart_embedder_packages",
     ":generate_dart_embedder_patch_resources_cc",