Sync the Event, EventTarget and CustomEvent interfaces with the spec

https://dom.spec.whatwg.org/#interface-event
https://dom.spec.whatwg.org/#interface-eventtarget
https://dom.spec.whatwg.org/#interface-customevent

Note that the EventListener argument for add/removeEventListener() is
named callback in the spec but left as listener here, as custom code in
Source/bindings/templates/methods.cpp to deal with missing arguments
depends on it. Sorting this out is left to http://crbug.com/353484

There are no observable changes to the generated code.

BUG=460722, 353484

Review URL: https://codereview.chromium.org/1005193002

git-svn-id: svn://svn.chromium.org/blink/trunk@191913 bbb929c8-8fbe-4397-9dbb-9b2b20218538
3 files changed
tree: 20c6110a38fa8ba6ba18f4ede51496b9416a7fd0
  1. third_party/