Implement Promise.race

Implement Promice.race static function. It is introduced in the Promises
latest draft and Promise.any is replaced with it.

BUG=295420

Review URL: https://chromiumcodereview.appspot.com/24728002

git-svn-id: svn://svn.chromium.org/blink/trunk@158391 bbb929c8-8fbe-4397-9dbb-9b2b20218538