Add user_prefs and visitedlink components to GN build.

content/public/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("//content/browser/browser.gni")
 import("//build/config/ui.gni")
 
 source_set("browser") {
   if (is_ios) {
     # iOS doesn't get the normal file list and only takes these whitelisted
@@ skipping 15 matching lines @@
   if (use_aura) {
     sources -= [ "context_factory.h" ]
   }
 
   configs += [ "//content:content_implementation" ]
 
   deps = [
     "//content/browser",
     "//skia",
   ]
+
+  # We expose skia headers in the public API.
+  forward_dependent_configs_from = [ "//skia" ]
 }