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 8dbdf774bb755c789d9d8cdc23e6f490c50f2b74..b814c3b15bcb635f4a23ecfd03bfb78e35bacf47 100644
--- a/ui/keyboard/BUILD.gn
+++ b/ui/keyboard/BUILD.gn
@@ -31,6 +31,7 @@ component("keyboard") {
     "//base",
     "//base/third_party/dynamic_annotations",
     "//content/public/browser",
+    "//content/public/common",
     "//url",
     "//ui/aura",
     "//ui/base",
@@ -70,8 +71,7 @@ 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") {
@@ -88,11 +88,10 @@ 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",