Promise init callback takes resolve and reject functions

The old DOM Promise spec is removed and the consensus[1] is updated.
PromiseResolver is removed and instead 2 functions are given to
the Promise init callback.

[1]: https://github.com/domenic/promises-unwrapping

Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=911213
WebKit: https://bugs.webkit.org/show_bug.cgi?id=120954

BUG=293904

Review URL: https://chromiumcodereview.appspot.com/23567043

git-svn-id: svn://svn.chromium.org/blink/trunk@158073 bbb929c8-8fbe-4397-9dbb-9b2b20218538