Move hardcoded extra fields to its own JSON5 file.

third_party/WebKit/Source/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("//build/config/chromecast_build.gni")
 import("//build/toolchain/toolchain.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 import("//third_party/WebKit/Source/bindings/bindings.gni")
@@ skipping 392 matching lines @@
 
   args = [
     rebase_path("../platform/RuntimeEnabledFeatures.json5", root_build_dir),
     "--output_dir",
     "$rel_blink_core_gen_dir/testing",
   ]
 }
 
 css_properties("make_core_generated_computed_style_base") {
   script = "../build/scripts/make_computed_style_base.py"
+  in_files = [ "css/ComputedStyleExtraFields.json5" ]
   other_inputs = [
     "../build/scripts/templates/fields/field.tmpl",
     "../build/scripts/templates/fields/base.tmpl",
     "../build/scripts/templates/fields/keyword.tmpl",
     "../build/scripts/templates/fields/primitive.tmpl",
     "../build/scripts/templates/fields/monotonic_flag.tmpl",
     "../build/scripts/templates/fields/storage_only.tmpl",
     "../build/scripts/templates/fields/external.tmpl",
     "../build/scripts/templates/ComputedStyleBase.cpp.tmpl",
     "../build/scripts/templates/ComputedStyleBase.h.tmpl",
@@ skipping 1043 matching lines @@
   sources = [
     "frame/csp/ContentSecurityPolicyFuzzer.cpp",
   ]
   deps = [
     ":core",
     "//third_party/WebKit/Source/platform:blink_fuzzer_test_support",
   ]
   dict = "//testing/libfuzzer/fuzzers/dicts/content_security_policy.dict"
   seed_corpus = "//testing/libfuzzer/fuzzers/content_security_policy_corpus"
 }