This refactoring makes it easier to write advanced tests and
gives full control over what's happening to the test code.
It also forces description for every test.
BUG=none
Review-Url: https://codereview.chromium.org/2891213002
Cr-Commit-Position: refs/heads/master@{#45412}
This method could be called on pause and will do stepInto next scheduled callback if any will happen until next break.
First implementation support only callbacks chained by Promise.prototype.then.
BUG=chromium:432469
R=yangguo@chromium.org,dgozman@chromium.org
Review-Url: https://codereview.chromium.org/2723273002
Cr-Commit-Position: refs/heads/master@{#43616}