Improve GN header checker, make //ui pass.

ui/gl/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")
 if (is_android) {
   import("//build/config/android/config.gni")
   import("//build/config/android/rules.gni")
 }
 
@@ skipping 100 matching lines @@
     "//third_party/switfshader/include",
     "//third_party/khronos",
     "//third_party/mesa/src/include",
     gl_binding_output_dir,
   ]
 
   all_dependent_configs = [ ":gl_config" ]
 
   deps = [
     ":generate_gl_bindings",
-    "//base",
     "//base/third_party/dynamic_annotations",
     "//gpu/command_buffer/common",
+    "//skia",
+  ]
+  public_deps = [
+    "//base",
     "//third_party/mesa:mesa_headers",
-    "//skia",
     "//ui/events/platform",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
 
-  # TODO(GYP) hook up once this is converted.
-  forward_dependent_configs_from = [ "//third_party/mesa:mesa_headers" ]
-
   if (is_win || is_android || is_linux) {
     sources += [
       "egl_util.cc",
       "egl_util.h",
       "gl_context_egl.cc",
       "gl_context_egl.h",
       "gl_fence_egl.cc",
       "gl_fence_egl.h",
       "gl_image_egl.cc",
       "gl_image_egl.h",
@@ skipping 191 matching lines @@
 }
 
 if (is_android) {
   generate_jar_jni("surface_jni_headers") {
     jni_package = "ui/gl"
     classes = [ "android/view/Surface.class" ]
   }
 
   generate_jni("gl_jni_headers") {
     deps = [ ":surface_jni_headers" ]
-    forward_dependent_configs_from = [ ":surface_jni_headers" ]
     sources = [
       "../android/java/src/org/chromium/ui/gl/SurfaceTextureListener.java",
       "../android/java/src/org/chromium/ui/gl/SurfaceTexturePlatformWrapper.java",
     ]
     jni_package = "ui/gl"
   }
 }