IDL: Generate union type containers

Source/bindings/scripts/scripts.gni

Index: Source/bindings/scripts/scripts.gni
diff --git a/Source/bindings/scripts/scripts.gni b/Source/bindings/scripts/scripts.gni
index b3641b38cbf269ca65bd2b7cde596e272c30d9c5..0e67d3d8dae28a2bc866d760a70af69c8b361038 100644
--- a/Source/bindings/scripts/scripts.gni
+++ b/Source/bindings/scripts/scripts.gni
@@ -179,13 +179,16 @@ template("idl_compiler") {
   }
 }
 
-# Runs the idl_compiler to generate IDL dictionary impl files.
+# Runs the idl_compiler to generate IDL dictionary and union impl files.
 #
 # Parameters:
 #   sources = a list of IDL files to process
 #   outputs = a list of files to write to
-template("idl_dictionary") {
-  output_dir = "$root_gen_dir/blink/"
+#   output_dir = the directory to put the output files
+#   individual_info = a filename of pickle file which contains idl union types
+#   target_component = component to generate code for
+template("idl_impl") {
+  dictionary_impl_output_dir = "$root_gen_dir/blink/"
 
   action(target_name) {
     script = "//third_party/WebKit/Source/bindings/scripts/idl_compiler.py"
@@ -199,12 +202,18 @@ template("idl_dictionary") {
       "--cache-dir",
       rebase_path(bindings_scripts_output_dir, root_build_dir),
       "--output-dir",
-      rebase_path(output_dir, root_build_dir),
+      rebase_path(invoker.output_dir, root_build_dir),
+      "--dictionary-impl-output-dir",
+      rebase_path(dictionary_impl_output_dir, root_build_dir),
       "--interfaces-info",
       rebase_path("$bindings_modules_output_dir/InterfacesInfoModules.pickle",
                   root_build_dir),
+      "--individual-info",
+      rebase_path(invoker.individual_info, root_build_dir),
+      "--target-component",
+      invoker.target_component,
       "--write-file-only-if-changed=1",
-      "--generate-dictionary-impl",
+      "--generate-impl",
       rebase_path(idl_files_list, root_build_dir),
     ]