Use |isolate| local variable in bindings, clean up comments

Source/bindings/scripts/code_generator_v8.py

 # 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
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 38 matching lines @@
 import sys
 
 # Path handling for libraries and templates
 # Paths have to be normalized because Jinja uses the exact template path to
 # determine the hash used in the cache filename, and we need a pre-caching step
 # to be concurrency-safe. Use absolute path because __file__ is absolute if
 # module is imported, and relative if executed directly.
 # If paths differ between pre-caching and individual file compilation, the cache
 # is regenerated, which causes a race condition and breaks concurrent build,
 # since some compile processes will try to read the partially written cache.
-module_path = os.path.dirname(os.path.realpath(__file__))
+module_path, module_filename = os.path.split(os.path.realpath(__file__))
 third_party_dir = os.path.normpath(os.path.join(
     module_path, os.pardir, os.pardir, os.pardir, os.pardir))
 templates_dir = os.path.normpath(os.path.join(
     module_path, os.pardir, 'templates'))
+# Make sure extension is .py, not .pyc or .pyo, so doesn't depend on caching
+module_pyname = os.path.splitext(module_filename)[0] + '.py'
 
 # jinja2 is in chromium's third_party directory.
 # Insert at 1 so at front to override system libraries, and
 # after path[0] == invoking script dir
 sys.path.insert(1, third_party_dir)
 import jinja2
 
 import idl_types
 from idl_types import IdlType
 import v8_callback_interface
@@ skipping 49 matching lines @@
             generate_contents = v8_callback_interface.generate_callback_interface
         else:
             header_template_filename = 'interface.h'
             cpp_template_filename = 'interface.cpp'
             generate_contents = v8_interface.generate_interface
         header_template = self.jinja_env.get_template(header_template_filename)
         cpp_template = self.jinja_env.get_template(cpp_template_filename)
 
         # Generate contents (input parameters for Jinja)
         template_contents = generate_contents(interface)
+        template_contents['code_generator'] = module_pyname
 
         # Add includes for interface itself and any dependencies
         interface_info = self.interfaces_info[interface_name]
         template_contents['header_includes'].add(interface_info['include_path'])
         template_contents['header_includes'] = sorted(template_contents['header_includes'])
         includes.update(interface_info.get('dependencies_include_paths', []))
         template_contents['cpp_includes'] = sorted(includes)
 
         # Render Jinja templates
         header_text = header_template.render(template_contents)
@@ skipping 59 matching lines @@
 
     # Create a dummy file as output for the build system,
     # since filenames of individual cache files are unpredictable and opaque
     # (they are hashes of the template path, which varies based on environment)
     with open(dummy_filename, 'w') as dummy_file:
         pass  # |open| creates or touches the file
 
 
 if __name__ == '__main__':
     sys.exit(main(sys.argv))