[iOS Clean] Created OverlayService.

ios/shared/chrome/browser/ui/dialogs/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.
+
+source_set("dialogs") {
+  deps = [
+    "//base",
+    "//components/strings",
+    "//components/url_formatter",
+    "//ios/web",
+    "//ui/base",
+  ]
+
+  sources = [
+    "nsurl_protection_space_util.h",
+    "nsurl_protection_space_util.mm",
+  ]
+
+  configs += [ "//build/config/compiler:enable_arc" ]
+}
+
+source_set("unit_tests") {
+  testonly = true
+
+  sources = [
+    "nsurl_protection_space_util_unittest.mm",
+  ]
+
+  deps = [
+    ":dialogs",
+    "//base",
+    "//components/strings",
+    "//ios/web",
+    "//ios/web/public/test/fakes",
+    "//testing/gtest",
+    "//ui/base",
+  ]
+
+  configs += [ "//build/config/compiler:enable_arc" ]
+}