Move content-side Feature Policy code into content/{common,child}/feature_policy

content/common/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("//mojo/public/tools/bindings/mojom.gni")
 import("//ppapi/features/features.gni")
 import("//sandbox/features.gni")
@@ skipping 89 matching lines @@
     "dom_storage/dom_storage_messages.h",
     "download/mhtml_save_status.cc",
     "download/mhtml_save_status.h",
     "drag_event_source_info.h",
     "drag_messages.h",
     "drag_traits.h",
     "dwrite_font_proxy_messages.h",
     "edit_command.h",
     "establish_channel_params.cc",
     "establish_channel_params.h",
+    "feature_policy/feature_policy.cc",
+    "feature_policy/feature_policy.h",
     "file_utilities_messages.h",
     "fileapi/file_system_messages.h",
     "font_cache_dispatcher_win.cc",
     "font_cache_dispatcher_win.h",
     "font_config_ipc_linux.cc",
     "font_config_ipc_linux.h",
     "font_list.cc",
     "font_list.h",
     "font_list_android.cc",
     "font_list_fontconfig.cc",
@@ skipping 478 matching lines @@
     "//ui/gfx/geometry/mojo",
     "//ui/gfx/mojo",
     "//url/mojo:url_mojom_gurl",
     "//url/mojo:url_mojom_origin",
   ]
 
   export_class_attribute = "CONTENT_EXPORT"
   export_define = "CONTENT_IMPLEMENTATION=1"
   export_header = "content/common/content_export.h"
 }