Add promise to pointerevent wpt automations
We return a promise from the APIs that send
user actions and we will fulfill them using
the callbacks in GPU benchmarking API.
Note that the callback in GPU benchmarking
is not called when the action is actually done.
Instead when the action is put in the queue to be
done. So that callback behavior needs to be fixed
later.
BUG=
638239
Committed:
https://crrev.com/698aa9d870b2cd6f52e75efd2989985f96d1d5db
Cr-Commit-Position: refs/heads/master@{#412611}