IDL: Support extended attributes on iterable<>, maplike<> and setlike<>

Such extended attributes are copied over to and affect the methods that
are automatically added by those definitions, e.g. keys() and values().

BUG=432683

Review URL: https://codereview.chromium.org/792903004

git-svn-id: svn://svn.chromium.org/blink/trunk@188406 bbb929c8-8fbe-4397-9dbb-9b2b20218538
5 files changed
tree: c556199baae9c18aa4dbf5a96619fbde682b82da
  1. third_party/