Remove a bunch of dead files found by missing_from_gn

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/*"]
 
 rel_sky_core_gen_dir = rebase_path(sky_core_output_dir, root_build_dir)
 
 source_set("libraries") {
   deps = [
+    "//base:base",
     "//gin",
     "//gpu/command_buffer/client:gles2_c_lib",
+    "//mojo/application",
     "//mojo/common",
-    "//mojo/application",
+    "//mojo/public/c/system:for_shared_library",
     "//mojo/public/cpp/bindings",
     "//mojo/public/cpp/utility",
-    "//mojo/public/c/system:for_shared_library",
     "//skia",
     "//sky/engine/wtf",
     "//third_party/angle:translator",
     "//third_party/iccjpeg",
     "//third_party/libpng",
     "//third_party/ots",
     "//third_party/qcms",
     "//third_party/zlib",
     "//url",
     "//v8",
@@ skipping 71 matching lines @@
     "$sky_core_output_dir/CSSTokenizer.cpp",
 
     # Generated from BisonCSSParser-in.cpp
     "$sky_core_output_dir/BisonCSSParser.cpp",
 
     # Generated from HTMLMetaElement-in.cpp
     "$sky_core_output_dir/HTMLMetaElement.cpp",
 
     # Additional .cpp files from the make_core_generated rules.
     "$sky_core_output_dir/CSSGrammar.cpp",
-
-    # Generated from make_css_property_metadata.py
-    "$sky_core_output_dir/CSSPropertyMetadata.cpp",
   ]
 
   configs += [
     "..:inside_blink",
   ]
 
   deps = [
     ":make_core_generated",
     ":prerequisites",
     "//gin",
@@ skipping 58 matching lines @@
     ":make_core_generated_fetch_initiator_type_names",
     ":make_core_generated_html_element_factory",
     ":make_core_generated_html_tokenizer_names",
     ":make_core_generated_media_type_names",
   ]
 }
 
 group("make_core_generated") {
   deps = [
     ":core_names",
+    ":make_core_generated_bison",
+    ":make_core_generated_css_property_metadata",
+    ":make_core_generated_css_value_keywords",
+    ":make_core_generated_event_factory",
+    ":make_core_generated_html_element_lookup_trie",
+    ":make_core_generated_html_element_type_helpers",
     ":make_core_generated_html_entity_table",
+    ":make_core_generated_make_parser",
+    ":make_core_generated_make_token_matcher",
+    ":make_core_generated_make_token_matcher_for_viewport",
     ":make_core_generated_media_feature_names",
     ":make_core_generated_media_features",
     ":make_core_generated_media_query_tokenizer_codepoints",
+    ":make_core_generated_style_builder",
     ":make_core_generated_style_property_shorthand",
-    ":make_core_generated_style_builder",
-    ":make_core_generated_css_value_keywords",
-    ":make_core_generated_html_element_type_helpers",
-    ":make_core_generated_event_factory",
-    ":make_core_generated_make_token_matcher",
-    ":make_core_generated_make_parser",
-    ":make_core_generated_make_token_matcher_for_viewport",
-    ":make_core_generated_html_element_lookup_trie",
-    ":make_core_generated_bison",
   ]
 }
 
 css_properties("make_core_generated_css_property_names") {
   script = "../build/scripts/make_css_property_names.py"
   outputs = [
     "$sky_core_output_dir/CSSPropertyNames.cpp",
     "$sky_core_output_dir/CSSPropertyNames.h",
   ]
 }
@@ skipping 297 matching lines @@
     "$sky_core_output_dir/{{source_name_part}}.h",
   ]
   args = [
     "{{source}}",
     rel_sky_core_gen_dir,
     bison_exe,
   ]
 
   deps = make_core_generated_deps
 }