port 2e329666

Original Commit Message:
    ... instead of doing stack magic.  This is a cleanup in preparation for the new
    generators implementation.

R=bmeurer@chromium.org, neis@chromium.org, joransiu@ca.ibm.com, michael_dawson@ca.ibm.com, mbrandy@us.ibm.com, bjaideep@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1882553003

Cr-Commit-Position: refs/heads/master@{#35417}