(Re-)introduce AncestorThrottle to handle 'X-Frame-Options'.

content/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/features.gni")
 import("//build/config/ui.gni")
 import("//media/media_options.gni")
 import("//ppapi/features/features.gni")
 import("//printing/features/features.gni")
 import("//third_party/WebKit/public/public_features.gni")
@@ skipping 578 matching lines @@
     "download/url_downloader.h",
     "fileapi/browser_file_system_helper.cc",
     "fileapi/browser_file_system_helper.h",
     "fileapi/fileapi_message_filter.cc",
     "fileapi/fileapi_message_filter.h",
     "fileapi/upload_file_system_file_element_reader.cc",
     "fileapi/upload_file_system_file_element_reader.h",
     "find_request_manager.cc",
     "find_request_manager.h",
     "font_list_async.cc",
+    "frame_host/ancestor_throttle.cc",
+    "frame_host/ancestor_throttle.h",
     "frame_host/cross_process_frame_connector.cc",
     "frame_host/cross_process_frame_connector.h",
     "frame_host/debug_urls.cc",
     "frame_host/debug_urls.h",
     "frame_host/frame_navigation_entry.cc",
     "frame_host/frame_navigation_entry.h",
     "frame_host/frame_tree.cc",
     "frame_host/frame_tree.h",
     "frame_host/frame_tree_node.cc",
     "frame_host/frame_tree_node.h",
@@ skipping 1378 matching lines @@
   if (!is_component_build) {
     public_deps = [
       ":browser",
     ]
   } else {
     public_deps = [
       "//third_party/leveldatabase",
     ]
   }
 }