Made a generator for .h files for implementations of CSSPropertyAPI.h

third_party/WebKit/Source/core/BUILD.gn

Index: third_party/WebKit/Source/core/BUILD.gn
diff --git a/third_party/WebKit/Source/core/BUILD.gn b/third_party/WebKit/Source/core/BUILD.gn
index e32d036877cd84402603bd7e4258a10922f70d4d..3d2e3090e8f5d5a53cb4dab396712a77c6525d6b 100644
--- a/third_party/WebKit/Source/core/BUILD.gn
+++ b/third_party/WebKit/Source/core/BUILD.gn
@@ -424,11 +424,15 @@ css_properties("make_core_generated_computed_style_base") {
   ]
 }
 
-css_properties("make_core_generated_css_property_descriptor") {
-  script = "../build/scripts/make_css_property_descriptor.py"
-  other_inputs = [ "../build/scripts/templates/CSSPropertyDescriptor.cpp.tmpl" ]
+css_properties("make_core_generated_css_property_api") {
+  script = "../build/scripts/make_css_property_api.py"
+  other_inputs = [
+    "../build/scripts/templates/CSSPropertyDescriptor.cpp.tmpl",
+    "../build/scripts/templates/CSSPropertyAPI.h.tmpl",
+  ]
   outputs = [
     "$blink_core_output_dir/css/properties/CSSPropertyDescriptor.cpp",
+    "$blink_core_output_dir/css/properties/CSSPropertyAPI*.h",
   ]
 }
 
@@ -873,7 +877,7 @@ targets_generating_sources = [
   ":make_core_generated_css_primitive_value_unit_trie",
   ":make_core_generated_css_property_metadata",
   ":make_core_generated_computed_style_base",
-  ":make_core_generated_css_property_descriptor",
+  ":make_core_generated_css_property_api",
   ":make_core_generated_css_property_names",
   ":make_core_generated_cssom_types",
   ":make_core_generated_event_factory",