Add migration code for the EnabledPlugins and DisabledPlugins policies.

chrome/browser/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/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 1871 matching lines @@
       "plugins/plugin_finder.cc",
       "plugins/plugin_finder.h",
       "plugins/plugin_info_message_filter.cc",
       "plugins/plugin_info_message_filter.h",
       "plugins/plugin_infobar_delegates.cc",
       "plugins/plugin_infobar_delegates.h",
       "plugins/plugin_metadata.cc",
       "plugins/plugin_metadata.h",
       "plugins/plugin_observer.cc",
       "plugins/plugin_observer.h",
+      "plugins/plugin_policy_handler.cc",
+      "plugins/plugin_policy_handler.h",
       "plugins/plugin_prefs.cc",
       "plugins/plugin_prefs.h",
       "plugins/plugin_prefs_factory.cc",
       "plugins/plugin_prefs_factory.h",
       "plugins/plugin_status_pref_setter.cc",
       "plugins/plugin_status_pref_setter.h",
       "plugins/plugin_utils.cc",
       "plugins/plugin_utils.h",
       "plugins/plugins_field_trial.cc",
       "plugins/plugins_field_trial.h",
@@ skipping 2384 matching lines @@
   # linking all of the test support.
   static_library("pepper_cdm_test_constants") {
     testonly = true
     visibility = [ "//chrome/*" ]
     sources = [
       "media/pepper_cdm_test_constants.cc",
       "media/pepper_cdm_test_constants.h",
     ]
   }
 }