Add more components_unittests to GN build

components/network_hints/renderer/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # GYP version: components/network_hints.gypi:predictor_renderer
 source_set("renderer") {
   sources = [
     "dns_prefetch_queue.cc",
     "dns_prefetch_queue.h",
     "prescient_networking_dispatcher.cc",
     "prescient_networking_dispatcher.h",
     "renderer_dns_prefetch.cc",
     "renderer_dns_prefetch.h",
     "renderer_preconnect.cc",
     "renderer_preconnect.h",
   ]
 
   public_deps = [
     "//components/network_hints/common",
     "//content/public/renderer",
     "//third_party/WebKit/public:blink",
   ]
 }
+
+source_set("unit_tests") {
+  testonly = true
+  sources = [
+    "dns_prefetch_queue_unittest.cc",
+    "renderer_dns_prefetch_unittest.cc",
+  ]
+  deps = [
+    ":renderer",
+    "//testing/gtest",
+  ]
+}