IDL: Generate union type containers

Source/bindings/core/v8/BUILD.gn

Index: Source/bindings/core/v8/BUILD.gn
diff --git a/Source/bindings/core/v8/BUILD.gn b/Source/bindings/core/v8/BUILD.gn
index 3af4b6459553f594b624b4f462cf50eaed25d737..b0419fb24f5aff2bcb9e8599dc4ab355216e78e1 100644
--- a/Source/bindings/core/v8/BUILD.gn
+++ b/Source/bindings/core/v8/BUILD.gn
@@ -13,7 +13,7 @@ visibility = [ "//third_party/WebKit/Source/*" ]
 # bindings_core_v8_generated in core/v8/generated.gyp
 group("bindings_core_v8_generated") {
   deps = [
-    ":bindings_core_dictionary_impl_generated",
+    ":bindings_core_impl_generated",
     ":bindings_core_v8_generated_aggregate",
     ":bindings_core_v8_generated_individual",
   ]
@@ -34,9 +34,14 @@ idl_compiler("bindings_core_v8_generated_individual") {
   target_component = "core"
 }
 
-# bindings_core_dictionary_impl_generated in Source/bindings/core/v8/generated.gyp
-idl_dictionary("bindings_core_dictionary_impl_generated") {
+# bindings_core_impl_generated in Source/bindings/core/v8/generated.gyp
+idl_impl("bindings_core_impl_generated") {
   sources = core_dictionary_idl_files + core_testing_dictionary_idl_files
-  outputs = generated_core_dictionary_files +
+  outputs = bindings_core_generated_union_type_files +
+    generated_core_dictionary_files +
     generated_core_testing_dictionary_files
+  output_dir = bindings_core_v8_output_dir
+  target_component = "core"
+  component_wide_info =
+    "$bindings_core_output_dir/ComponentInfoCore.pickle"
 }