Make PermissionRequest::GetIconId return different types

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 741 matching lines @@
     "permissions/permission_infobar_delegate.cc",
     "permissions/permission_infobar_delegate.h",
     "permissions/permission_manager.cc",
     "permissions/permission_manager.h",
     "permissions/permission_manager_factory.cc",
     "permissions/permission_manager_factory.h",
     "permissions/permission_request.cc",
     "permissions/permission_request.h",
     "permissions/permission_request_id.cc",
     "permissions/permission_request_id.h",
-    "permissions/permission_request_impl.cc",
-    "permissions/permission_request_impl.h",
     "permissions/permission_request_manager.cc",
     "permissions/permission_request_manager.h",
     "permissions/permission_uma_util.cc",
     "permissions/permission_uma_util.h",
     "permissions/permission_util.cc",
     "permissions/permission_util.h",
     "platform_util.h",
     "platform_util_chromeos.cc",
     "platform_util_internal.h",
     "platform_util_mac.mm",
@@ skipping 1986 matching lines @@
       "net/firefox_proxy_settings.cc",
       "net/firefox_proxy_settings.h",
       "net/utility_process_mojo_proxy_resolver_factory.cc",
       "net/utility_process_mojo_proxy_resolver_factory.h",
       "obsolete_system/obsolete_system.h",
       "obsolete_system/obsolete_system_linux.cc",
       "obsolete_system/obsolete_system_mac.cc",
       "obsolete_system/obsolete_system_win.cc",
       "pdf/pdf_extension_util.cc",
       "pdf/pdf_extension_util.h",
+      "permissions/permission_request_impl.cc",
+      "permissions/permission_request_impl.h",
       "power/process_power_collector.cc",
       "power/process_power_collector.h",
       "process_singleton_modal_dialog_lock.cc",
       "process_singleton_modal_dialog_lock.h",
       "process_singleton_posix.cc",
       "process_singleton_startup_lock.cc",
       "process_singleton_startup_lock.h",
       "profile_resetter/brandcode_config_fetcher.cc",
       "profile_resetter/brandcode_config_fetcher.h",
       "profile_resetter/brandcoded_default_settings.cc",
@@ skipping 1506 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",
     ]
   }
 }