GitLab

This CL fixes bufferedAmount-after-send.html and removes it from the flaky
tests list.

BUG=520615

Review URL: https://codereview.chromium.org/1295723003

git-svn-id: svn://svn.chromium.org/blink/trunk@200812 bbb929c8-8fbe-4397-9dbb-9b2b20218538