Add missing dependency

sky/engine/core/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("//sky/engine/bindings/scripts/scripts.gni")
 import("//sky/engine/build/scripts/scripts.gni")
 import("//sky/engine/core/core.gni")
 
 visibility = ["//sky/engine/*"]
 
@@ skipping 253 matching lines @@
 }
 
 css_properties("make_core_generated_css_property_metadata") {
   script = "../build/scripts/make_css_property_metadata.py"
   other_inputs = [
     "../build/scripts/templates/CSSPropertyMetadata.cpp.tmpl",
   ]
   outputs = [
     "$sky_core_output_dir/CSSPropertyMetadata.cpp",
   ]
+
+  deps = [ ":core_names" ]
 }
 
 process_in_files("make_core_generated_css_value_keywords") {
   script = "../build/scripts/make_css_value_keywords.py"
 
   in_files = [
     "css/CSSValueKeywords.in",
     "css/SVGCSSValueKeywords.in",
   ]
   outputs = [
@@ skipping 230 matching lines @@
     "$sky_core_output_dir/{{source_name_part}}.h",
   ]
   args = [
     "{{source}}",
     rel_sky_core_gen_dir,
     bison_exe,
   ]
 
   deps = make_core_generated_deps
 }