Bindings tests should run the same code as prod code.

third_party/WebKit/Source/bindings/scripts/idl_compiler.py

 #!/usr/bin/python
 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 104 matching lines @@
         target_definitions = definitions[self.target_component]
         output_code_list = self.code_generator.generate_code(
             target_definitions, interface_name)
         for output_path, output_code in output_code_list:
             write_file(output_code, output_path)
 
     def compile_file(self, idl_filename):
         self.compile_and_write(idl_filename)
 
 
-def generate_bindings(code_generator_class, options, input_filename):
-    info_provider = create_component_info_provider(
-        options.info_dir, options.target_component)
+def generate_bindings(code_generator_class, info_provider, options,
+                      input_filenames):
     idl_compiler = IdlCompiler(
         output_directory=options.output_directory,
         cache_directory=options.cache_directory,
         code_generator_class=code_generator_class,
         info_provider=info_provider,
         target_component=options.target_component)
-    idl_compiler.compile_file(input_filename)
+
+    for idl_filename in input_filenames:
+        idl_compiler.compile_file(idl_filename)
 
 
-def generate_dictionary_impl(code_generator_class, options, input_filename):
-    info_provider = create_component_info_provider(
-        options.info_dir, options.target_component)
+def generate_dictionary_impl(code_generator_class, info_provider, options,
+                             input_filenames):
     idl_compiler = IdlCompiler(
         output_directory=options.impl_output_directory,
         cache_directory=options.cache_directory,
         code_generator_class=code_generator_class,
         info_provider=info_provider,
         target_component=options.target_component)
 
-    idl_filenames = read_idl_files_list_from_file(input_filename,
-                                                  is_gyp_format=True)
-    for idl_filename in idl_filenames:
+    for idl_filename in input_filenames:
         idl_compiler.compile_file(idl_filename)
 
 
-def generate_union_type_containers(code_generator_class, options):
-    info_provider = create_component_info_provider(
-        options.info_dir, options.target_component)
-    if not info_provider.interfaces_info:
-        raise Exception('Interfaces info is required to generate '
-                        'union types containers')
+def generate_union_type_containers(code_generator_class, info_provider,
+                                   options):
     generator = code_generator_class(
         info_provider,
         options.cache_directory,
         options.output_directory,
         options.target_component)
     output_code_list = generator.generate_code()
     for output_path, output_code in output_code_list:
         write_file(output_code, output_path)
 
 
-def generate_callback_function_impl(code_generator_class, options):
-    info_provider = create_component_info_provider(
-        options.info_dir, options.target_component)
+def generate_callback_function_impl(code_generator_class, info_provider,
+                                    options):
     generator = code_generator_class(
         info_provider,
         options.cache_directory,
         options.output_directory,
         options.target_component)
     output_code_list = generator.generate_code()
     for output_path, output_code in output_code_list:
         write_file(output_code, output_path)
 
 
 def main():
     options, input_filename = parse_options()
+    info_provider = create_component_info_provider(
+        options.info_dir, options.target_component)
     if options.generate_impl:
+        if not info_provider.interfaces_info:
+            raise Exception('Interfaces info is required to generate '
+                            'union types containers')
         # |input_filename| should be a file which contains a list of IDL
         # dictionary paths.
-        generate_dictionary_impl(CodeGeneratorDictionaryImpl, options,
-                                 input_filename)
-        generate_union_type_containers(CodeGeneratorUnionType, options)
-        generate_callback_function_impl(CodeGeneratorCallbackFunction, options)
+        input_filenames = read_idl_files_list_from_file(input_filename,
+                                                        is_gyp_format=True)
+        generate_dictionary_impl(CodeGeneratorDictionaryImpl, info_provider,
+                                 options, input_filenames)
+        generate_union_type_containers(CodeGeneratorUnionType, info_provider,
+                                       options)
+        generate_callback_function_impl(CodeGeneratorCallbackFunction,
+                                        info_provider, options)
     else:
         # |input_filename| should be a path of an IDL file.
-        generate_bindings(CodeGeneratorV8, options, input_filename)
+        generate_bindings(CodeGeneratorV8, info_provider, options,
+                          [input_filename])
 
 
 if __name__ == '__main__':
     sys.exit(main())