Improve GN header checker, make //ui pass.

content/shell/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("//tools/grit/repack.gni")
 import("//tools/grit/grit_rule.gni")
 if (is_android) {
   import("//build/config/android/config.gni")
@@ skipping 185 matching lines @@
     "renderer/test_runner/web_test_delegate.h",
     "renderer/test_runner/web_test_proxy.cc",
     "renderer/test_runner/web_test_proxy.h",
     "renderer/test_runner/web_test_runner.h",
     "renderer/webkit_test_runner.cc",
     "renderer/webkit_test_runner.h",
   ]
 
   defines = [ "CONTENT_SHELL_VERSION=\"$content_shell_version\"" ]
 
+  public_deps = [
+    # This exposes all public content APIs.
+    "//content/public/app:both",
+    "//content/public/browser",
+    "//content/public/common",
+    "//content/public/plugin",
+    "//content/public/renderer",
+    "//content/public/utility",
+  ]
   deps = [
     ":resources",
     "//base",
     "//base:base_static",
     "//base/allocator",
     "//base/third_party/dynamic_annotations",
     "//cc",
     "//components/crash/app",
     "//components/web_cache/renderer",
     "//content:resources",
     "//content/app/resources",
     "//content/app/strings",
     "//content/gpu",
-    "//content/public/app:both",
-    "//content/public/browser",
-    "//content/public/common",
-    "//content/public/plugin",
-    "//content/public/renderer",
-    "//content/public/utility",
     "//content/test:layouttest_support",
     "//gin",
     "//gpu",
     "//ipc",
     "//media",
     "//net",
     "//net:net_resources",
     "//skia",
     "//storage/browser",
     "//third_party/WebKit/public:blink",
@@ skipping 239 matching lines @@
   if (is_android && !is_android_webview_build) {
     # Some tests rely on this tool. It might be nicer if these tests relied on
     # image diff rather than having content shell depend on it.
     datadeps = [
       "//tools/imagediff($host_toolchain)",
     ]
   }
 }
 
 }