Improve GN header checker, make //ui pass.

ui/views/examples/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/ui.gni")
 
 component("views_examples_lib") {
   testonly = true
 
   sources = [
@@ skipping 55 matching lines @@
   deps = [
     "//base",
     "//skia",
     "//third_party/icu",
     "//ui/base",
     "//ui/events",
     "//ui/gfx",
     "//ui/gfx/geometry",
     "//ui/resources",
     "//ui/resources:ui_test_pak",
+    "//ui/views",
   ]
 
   if (is_win) {
     deps += [ "//third_party/wtl" ]
 
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     cflags = [ "/wd4267" ]
   }
 
   if (use_aura) {
     deps += [ "//ui/aura" ]
   }
 }
 
 executable("views_examples_exe") {
   testonly = true
 
   sources = [
     "examples_main.cc",
   ]
 
   deps = [
     ":views_examples_lib",
     "//base",
     "//base:i18n",
     "//ui/base",
     "//ui/compositor",
     "//ui/compositor:test_support",
     "//ui/gfx",
+    "//ui/gl",
     "//ui/resources:ui_test_pak",
     "//ui/views",
     "//ui/views:test_support",
+    "//ui/wm",
   ]
 
   if (use_aura) {
     deps += [ "//ui/aura" ]
   }
+  if (use_x11) {
+    deps += [ "//ui/gfx/x" ]
+  }
 }
 
 component("views_examples_with_content_lib") {
   testonly = true
   sources = [
     "examples_window_with_content.cc",
     "examples_window_with_content.h",
     "views_examples_with_content_export.h",
     "webview_example.cc",
     "webview_example.h",
@@ skipping 22 matching lines @@
 
   defines = [ "VIEWS_EXAMPLES_WITH_CONTENT_IMPLEMENTATION" ]
 
   deps = [
     ":views_examples_with_content_lib",
     "//base",
     "//content",
     "//ui/views_content_client",
   ]
 }