Eagerly finalize V8AbstractEventListeners.

The listener's wrapper needs to be promptly cleared so as to prevent
untidy accesses to a poisoned heap by v8's GC if the listener is instead
lazily swept & finalized.

R=haraken
BUG=491488

Review URL: https://codereview.chromium.org/1263953002

git-svn-id: svn://svn.chromium.org/blink/trunk@199721 bbb929c8-8fbe-4397-9dbb-9b2b20218538
1 file changed