mac: Add tests for reading images from NSPasteboard.

ui/base/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.
 
 import("//build/buildflag_header.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//ui/base/ui_features.gni")
@@ skipping 699 matching lines @@
   ]
   outputs = [
     "{{bundle_resources_dir}}/" +
         "{{source_root_relative_dir}}/{{source_file_part}}",
   ]
 }
 
 # GYP version: ui/base/ui_base_tests.gyp:ui_base_unittests
 test("ui_base_unittests") {
   sources = [
+    "clipboard/clipboard_mac_unittest.mm",
     "clipboard/clipboard_util_mac_unittest.mm",
     "l10n/l10n_util_mac_unittest.mm",
     "l10n/l10n_util_unittest.cc",
     "l10n/l10n_util_win_unittest.cc",
     "l10n/time_format_unittest.cc",
     "layout_unittest.cc",
     "material_design/material_design_controller_unittest.cc",
     "models/tree_node_iterator_unittest.cc",
     "resource/data_pack_literal.cc",
     "resource/data_pack_unittest.cc",
@@ skipping 220 matching lines @@
 if (is_mac) {
   mac_framework_bundle("ui_unittests_framework") {
     testonly = true
     deps = [
       "//ui/resources:ui_test_pak_bundle_data",
     ]
     info_plist = "test/framework-Info.plist"
     output_name = "ui_unittests Framework"
   }
 }