Add context menu when long press on a reading list entry

ios/chrome/browser/ui/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("//build/config/ios/rules.gni")
 
 source_set("ui") {
   sources = [
     "UIView+SizeClassSupport.h",
     "UIView+SizeClassSupport.mm",
@@ skipping 192 matching lines @@
 source_set("ui_internal") {
   sources = [
     "browser_container_view.h",
     "browser_container_view.mm",
     "browser_view_controller.h",
     "browser_view_controller.mm",
     "browser_view_controller_dependency_factory.h",
     "browser_view_controller_dependency_factory.mm",
     "chrome_web_view_factory.h",
     "chrome_web_view_factory.mm",
+    "clipboard_util.h",
+    "clipboard_util.mm",
     "external_file_controller.h",
     "external_file_controller.mm",
     "external_file_remover.h",
     "external_file_remover.mm",
     "fade_truncated_label.h",
     "fade_truncated_label.mm",
     "fullscreen_controller.h",
     "fullscreen_controller.mm",
     "key_commands_provider.h",
     "key_commands_provider.mm",
@@ skipping 196 matching lines @@
     "//ios/chrome/browser/tabs:tabs_internal",
     "//ios/chrome/browser/ui/omnibox:omnibox_internal",
     "//ios/chrome/browser/ui/toolbar",
     "//ios/chrome/test/base:perf_test_support",
     "//testing/gtest",
     "//third_party/ocmock",
     "//ui/base:test_support",
   ]
   libs = [ "UIKit.framework" ]
 }