EDK: Move ref counting classes to mojo/edk/util.

mojo/edk/util/BUILD.gn

Index: mojo/edk/util/BUILD.gn
diff --git a/mojo/edk/util/BUILD.gn b/mojo/edk/util/BUILD.gn
index 2ec20fc2b027eae1660e18c33b4f16b403900df7..775e1a6f92e2002735fe5805fb1e6ca426e988da 100644
--- a/mojo/edk/util/BUILD.gn
+++ b/mojo/edk/util/BUILD.gn
@@ -7,8 +7,49 @@ import("../mojo_edk.gni")
 mojo_edk_source_set("util") {
   sources = [
     "make_unique.h",
+    "ref_counted.h",
+    "ref_counted_internal.h",
+    "ref_ptr.h",
+    "ref_ptr_internal.h",
     "scoped_file.h",
   ]
 
   mojo_edk_configs = [ "mojo/edk/system:system_config" ]
+
+  mojo_sdk_public_deps = [ "mojo/public/cpp/system" ]
+}
+
+mojo_edk_source_set("unittests") {
+  testonly = true
+  mojo_edk_visibility = [ "mojo/edk/system:mojo_system_unittests" ]
+
+  sources = [
+    "ref_counted_unittest.cc",
+  ]
+
+  mojo_sdk_deps = [ "mojo/public/cpp/system" ]
+
+  deps = [
+    ":util",
+    "//testing/gtest",
+  ]
+}
+
+mojo_edk_source_set("perftests") {
+  testonly = true
+  mojo_edk_visibility = [ "mojo/edk/system:mojo_system_perftests" ]
+
+  sources = [
+    "ref_counted_perftest.cc",
+  ]
+
+  deps = [
+    ":util",
+    "//testing/gtest",
+  ]
+
+  mojo_edk_deps = [
+    "mojo/edk/system/test",
+    "mojo/edk/system/test:perf",
+  ]
 }