html_viewer/Mandoline: Avoid subclassing WebLayerImpl

components/html_viewer/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/module_args/v8.gni")
 import("//mojo/public/mojo_application.gni")
 import("//testing/test.gni")
 import("//tools/grit/grit_rule.gni")
 import("//tools/grit/repack.gni")
 
@@ skipping 99 matching lines @@
     "test_html_viewer_impl.cc",
     "test_html_viewer_impl.h",
     "touch_handler.cc",
     "touch_handler.h",
     "web_clipboard_impl.cc",
     "web_clipboard_impl.h",
     "web_cookie_jar_impl.cc",
     "web_cookie_jar_impl.h",
     "web_graphics_context_3d_command_buffer_impl.cc",
     "web_graphics_context_3d_command_buffer_impl.h",
-    "web_layer_impl.cc",
-    "web_layer_impl.h",
     "web_layer_tree_view_impl.cc",
     "web_layer_tree_view_impl.h",
     "web_mime_registry_impl.cc",
     "web_mime_registry_impl.h",
     "web_notification_manager_impl.cc",
     "web_notification_manager_impl.h",
     "web_socket_handle_impl.cc",
     "web_socket_handle_impl.h",
     "web_storage_namespace_impl.cc",
     "web_storage_namespace_impl.h",
@@ skipping 230 matching lines @@
 
   data_deps = [
     ":html_viewer",
     "//components/mus",
   ]
 
   if (is_linux && !is_android) {
     data_deps += [ "//components/font_service" ]
   }
 }