Improve GN header checker, make //ui pass.

extensions/generated_extensions_api.gni

 # 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.
 
 # Defines a static library corresponding to the output of schema compiler tools
 # over a set of extensions API schemas (IDL or JSON format.) The library target
 # has implicit hard dependencies on all schema files listed by the invoker and
 # is itself a hard dependency.
 #
 # Invocations of this template may use the following variables:
@@ skipping 158 matching lines @@
         "--impl-dir=" + rebase_path(impl_dir, "//"),
         "--include-rules=$schema_include_rules" ]
         + rebase_path(sources, root_build_dir)
         + rebase_path(uncompiled_sources, root_build_dir)
     }
   }
 
   source_set(target_name) {
     sources = []
     deps = []
-    
+    public_deps = []
+
     if (schemas) {
       sources += get_target_outputs(":$schema_generator_name")
-      deps += [
-        ":$schema_generator_name",
-        "//tools/json_schema_compiler:generated_api_util",
-      ]
+      public_deps += [ ":$schema_generator_name" ]
+      deps += [ "//tools/json_schema_compiler:generated_api_util" ]
     }
 
     if (bundle) {
       sources += get_target_outputs(":$bundle_generator_schema_name")
       deps += [ ":$bundle_generator_schema_name" ]
     }
 
     if (bundle_registration) {
       sources += get_target_outputs(":$bundle_generator_registration_name")
       deps += [ ":$bundle_generator_registration_name" ]
     }
 
     if (defined(invoker.deps)) {
       deps += invoker.deps
     }
     direct_dependent_configs = [ ":$generated_config_name" ]
 
     if (defined(invoker.visibility)) {
       visibility = invoker.visibility
     }
     if (defined(invoker.output_name)) {
       output_name = invoker.output_name
     }
   }
 }