Move display_service_unittests to services_unittests.

services/service_manager/public/cpp/test/BUILD.gn

 # Copyright 2016 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.
 
 import("//testing/test.gni")
 
-# NOTE: Don't depend on this target directly. Instead use the service_test
-# template from //services/service_manager/public/tools/test/service_test.gni.
-source_set("run_all_service_tests") {
+# Only depend on this target if you're trying to implement a custom service
+# test runner.
+source_set("common_initialization") {
   testonly = true
 
   sources = [
-    "run_all_service_tests.cc",
+    "common_initialization.cc",
+    "common_initialization.h",
     "service_test_catalog.h",
   ]
 
   deps = [
     "//base",
     "//base/test:test_support",
     "//mojo/edk/system",
     "//services/catalog:lib",
     "//services/service_manager/background:lib",
     "//services/service_manager/public/cpp/standalone_service",
   ]
 
   if (is_android) {
     deps += [ "//mojo/android:libsystem_java" ]
   }
 }
+
+# NOTE: Don't depend on this target directly. Instead use the service_test
+# template from //services/service_manager/public/tools/test/service_test.gni.
+source_set("run_all_service_tests") {
+  testonly = true
+
+  sources = [
+    "run_all_service_tests.cc",
+  ]
+
+  deps = [
+    ":common_initialization",
+    "//base",
+    "//base/test:test_support",
+  ]
+}