Add chrome://site-tiles-internals/

components/ntp_tiles/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.
 
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
 static_library("ntp_tiles") {
   sources = [
@@ skipping 13 matching lines @@
     "ntp_tile.h",
     "ntp_tile_source.h",
     "popular_sites.cc",
     "popular_sites.h",
     "pref_names.cc",
     "pref_names.h",
     "switches.cc",
     "switches.h",
     "webui/popular_sites_internals_message_handler.cc",
     "webui/popular_sites_internals_message_handler.h",
+    "webui/popular_sites_internals_message_handler_client.h",
+    "webui/site_tiles_internals_message_handler.cc",
+    "webui/site_tiles_internals_message_handler.h",
+    "webui/site_tiles_internals_message_handler_client.h",
   ]
 
   public_deps = [
     "//base",
     "//components/history/core/browser",
     "//components/suggestions",
   ]
   deps = [
     "//components/data_use_measurement/core",
     "//components/favicon/core",
@@ skipping 53 matching lines @@
 }
 
 if (is_android) {
   java_cpp_enum("ntp_tiles_enums_java") {
     sources = [
       "metrics.h",
       "ntp_tile_source.h",
     ]
   }
 }