Improve GN header checker, make //ui pass.

ui/keyboard/BUILD.gn

Index: ui/keyboard/BUILD.gn
diff --git a/ui/keyboard/BUILD.gn b/ui/keyboard/BUILD.gn
index 3133f998a5054d1b7ee67aae6fca34c7edf96d0d..8fa3240b644a7d12d8eb19339b668f7b369d0134 100644
--- a/ui/keyboard/BUILD.gn
+++ b/ui/keyboard/BUILD.gn
@@ -83,8 +83,7 @@ grit("resources_grit") {
 copy("resources") {
   sources = [ "$target_gen_dir/keyboard_resources.pak" ]
   outputs = [ "$root_out_dir/keyboard_resources.pak" ]
-  deps = [ ":resources_grit" ]
-  forward_dependent_configs_from = deps
+  public_deps = [ ":resources_grit" ]
 }
 
 test("keyboard_unittests") {
@@ -101,11 +100,10 @@ test("keyboard_unittests") {
     "//content",
     "//skia",
     "//testing/gtest",
-    "//ui/aura",
     "//ui/aura:test_support",
-    "//ui/base",
-    "//ui/compositor",
+    "//ui/base:test_support",
     "//ui/compositor:test_support",
+    "//ui/events:test_support",
     "//ui/gfx",
     "//ui/gfx/geometry",
     "//ui/gl",